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SAT problem solving practice test 04. SAT problem solving practice test 04 1. If a² = 12, then a4 = 2. If n is even, which of the following cannot be odd? I n + 3II 3nIII n² - 1 A. 3. A. 4. 5. A. 8p B. pq C. pq + 27 D. 6. 7. n is an integer chosen at random from the set p is chosen at random from the set What is the probability that n + p = 23 ? 8. 9. 10. Test information 10 questions 12 minutes This is just one of many free SAT problem solving tests available on majortests.com. . * SAT is a registered trademark of the College Board, which was not involved in the production of, and does not endorse, this product.

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Se connecter à Facebook. Mind reading | Brilliant Math & Science Wiki. In Las Vegas, a street artist said that he could read your mind. He asked you to think of a certain two digit number, multiply it by add to it, and then multiply it by As you rattle off your result, he is able to confidently state the number that you were thinking of. How did he do this? Let's say that the ordinary random citizen, clueless of maths (you?) , thought of a number with and . Now, we proceed step-by-step to demonstrate you how he blew your (clueless?) Mind. First of all, the number you chose in your mind can be written as Let be the number that you rattle off as your result to the mathe-magician. Cards trick: You pick a card from a deck of cards, remember it, and put it back in. Birthday Card Trick: The below 5 cards can be used to find the Birthday of friends/relatives. A magician (read mathematician) selects five spectators by some random process (say throwing five balls blindfolded).

SAT Reasoning Perfect Score | Brilliant Math & Science Wiki. How many triples of integers are there such that (A) (B) (C) (D) (E) Correct Answer: B Solution: We check all possible cases as follows: If , then which gives solution. If , then or which gives solutions. If , then or which gives solutions. If , then or or or which gives solutions. If , then or or or which gives solutions. If , then or which gives solutions. If , then or which gives solutions. How many triples of integers are there such that (A) (B) (C) (D) (E) Correct Answer: E Solution: We check all possible cases as follows: If , then or which gives solutions. If where and are positive integers, then has at most positive divisors. SAT General Tips | Brilliant Math & Science Wiki. The following tips are useful when working on SAT problems. Follow the order of operations. Read the entire question carefully. The simplest choice may not be the correct one.The complicated choice may not be the correct one.Look for short-cuts.If you can, verify your choice.

Just because a number appears in the question doesn't mean it is the answer.Plug and check.Identify irrelevant information.Eliminate obviously wrong answers. Numbers Know the properties of even and odd numbers. Number Line Consecutive integers: …,n−1,n,n+1,n+2,n+3…, where n is an integer. Factors, Divisibility, and Remainders Fractions and Decimals When dealing with fractions, one whole unit = 1. Ratios, Proportions, and Percents Know the properties of proportions.Pay attention to units. Sequences and Series For an arithmetic sequence, an​=a1​+(n−1)d. Algebraic Manipulations Follow the order of operations. Polynomials a2−b2=(a−b)(a+b)(a±b)2=a2±2ab+b2 Exponents Know the rules of exponents.

Change the Subject Inequalities Functions. SAT Reasoning Perfect Score | Brilliant Math & Science Wiki. Information Compression | Brilliant Math & Science Wiki. When solving logic puzzles, it is often useful to think combinatorially: consider the size of the space of possible outcomes, and then to consider how those outcomes can be distinguished given the tools of the problem. This kind of analysis will generally give some bounds on possible solutions, but will often point the way toward a successful solution as well. There are eight identical-looking coins; one of these coins is odd and is known to be heavier than the other coins. What is the minimum number of weighing needed to identify the fake coin with a two-pan balance scale without weights?

Select from the given coins two groups of three coins each and put them on the opposite cups of the scale. If they weigh the same, the fake is among the remaining two coins, and weighing these two coins will identify the heavier fake. If the first weighing does not yield a balance, the heavier fake is among the three heavier coins. Converting Decimals and Fractions | Brilliant Math & Science Wiki. When converting between decimals and fractions, we have to realize that fractions are closed under rational numbers. That is, any number that can be written in fractional form is a rational number.

This includes integers, terminating decimals, and non-terminating or repeating decimals. An integer can simply be written as fraction by making the numerator the number itself and the denominator one. For example, the number can be written in fractional form as . A terminating decimal can be written as fraction by writing it the way you say it. For example, the decimal is one and one half or . Adding the terms gives . A repeating decimal can also be written as fraction using algebraic method. If a number doesn't have the above property, then it is not a rational number. Given , which of the numbers can be written in fractional form?

Prime Numbers: Level 4 Challenges Practice Problems Online. Set Theory | Brilliant Math & Science Wiki. An important quantity related to a set is the cardinality of a set , denoted , which counts how many elements the set contains. If this is finite, then it is just a number, but if it is infinite, there are some distinctions worth making.

There are countably infinite sets as well as uncountably infinite. Here, a countable set is one that can be put in bijection with the positive integers. An uncountable set is, in a precise sense, larger than a countable set, even though both have infinitely many elements. In fact, the power set of a countable set is an uncountable set. The question of whether there is a size of infinite in between countable and uncountable is known as the continuum hypothesis, and remains open, although it has been proven that this problem is independent of ZFC. This means that it can be neither proven nor disproven with the axioms of ZFC set theory.

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Logical Reasoning: Level 5 Challenges Practice Problems Online. You are the ruler of a great empire and you have decided to throw another celebration tomorrow. However, apparently you were forgetful of the near disaster that happened in the last celebration, and decide to hatch your own plan with poison. For during this celebration, one of your most hated rivals will come, thinking that you have finally given up your fight and you held this celebration in part to surrender to your rival's superiority. You decide to pour some drops of that same deadly poison (that have no symptoms except death 10 to 20 hours later) into his glass; however, you do not want to look guilty, so to push the blame away you will insert some poison in your own drink that will make you sick after 10 to 20 hours with some worrisome but definitely non-lethal symptoms.

You have already inserted the deadly poison in one glass and your non-lethal poison in another glass out of the 1000 glasses, but because of your forgetfulness you forgot which glasses had the poisons!

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LZ TCH PGS. SMALL. SC. LAL. Information Compression | Brilliant Math & Science Wiki. Absolute Truth. Absolute Truth - Inflexible Reality "Absolute truth" is defined as inflexible reality: fixed, invariable, unalterable facts. For example, it is a fixed, invariable, unalterable fact that there are absolutely no square circles and there are absolutely no round squares. Absolute Truth vs. Relativism While absolute truth is a logical necessity, there are some religious orientations (atheistic humanists, for example) who argue against the existence of absolute truth.

Humanism's exclusion of God necessitates moral relativism. Humanist John Dewey (1859-1952), co-author and signer of the Humanist Manifesto 1 (1933), declared, "There is no God and there is no soul. Hence, there are no needs for the props of traditional religion. Absolute Truth - A Logical Necessity You can't logically argue against the existence of absolute truth. "There are no absolutes.

" "Truth is relative. " "Who knows what the truth is, right? " "No one knows what the truth is. " Read Absolute Truth Page 2 Now! Triangles | Brilliant Math & Science Wiki. Main article: Area of a Triangle When determining the area of a triangle, note that a triangle can be thought of as half of a parallelogram. The following picture should make this point clear: Because the area of a parallelogram is equal to the product of its base and height, the area of a triangle is simply half of that area.

The area of a triangle is , where is the length of the base and is the height. What is the area of a triangle with base 10 and height 6? Nihar and Andrew are trying to find the area of using the formula Nihar mistakenly multiplies base by height from (instead of ). Andrew mistakenly multiplies base by height from (instead of ). Find the actual area of triangle . For more advanced methods of finding the area of a triangle, such as Heron's Formula, see the wiki linked at the top of this section. Solve proportions: word problems (Algebra 1 practice)

GEOMETRY

Modular Arithmetic. Number Theory Modular Arithmetic (Congruences) Number Theory Contents Page Contents Definition On this page, a, b, k, and m are always integers. A≡b (mod m) is read as "a is congruent to b mod m". In a simple, but not wholly correct way, we can think of a≡b (mod m) to mean "a is the remainder when b is divided by m". For instance, 2≡12 (mod 10) means that 2 is the remainder when 12 is divided by 10. More formally, we can define: a≡b (mod m) ⇔m|(a-b), where | means "evenly divides". [1.1] That is, a≡b (mod m) implies that m divides (a−b). So, if 5≡22 (mod 17), then 17|(22-5), as it does (it is 1) We can also define a≡b (mod m) as: a≡b (mod m) ≡ a=b+km [1.2] where k is some integer. So, if 5≡22 (mod 17), then 5=22+17k, where, here, k=−1 We sometimes have a preference for k to be a positive or negative integer such that a is the least positive value satisfying b+km.

Basics Identity Addition We can add (and therefore subtract) congruences, so: a≡b (mod m), and c≡d (mod m)↔a+c≡b+d (mod m) [3.0] Proof. The order modulo n. If you exponentiate an integer number modulo another one, you may observe curious effects. For instance, 33 = 27 = 12 mod 15, whereas 34 = 81 = 6 mod 15. That is, multiplying 12 by 3 modulo 15 yields a number smaller than 12!?

Or, if you calculate modulo 24 (the number of hours of a day), you obtain 33 = 27 = 3 mod 24. Funny, uh? For some numbers m > 1 you even can find a power r such that mr = 1 mod n. The order of an integer m modulo a (natural) number n is defined to be the smallest positive integer power r such that mr = 1 mod n. The order r of m modulo n is shortly denoted by ordn(m).

Even worse, sometimes there are numbers with a positive power that vanishes. It is an important group theoretic result that if n is prime, then any integer relatively prime to n has a finite order. The dots (...) represent the fact that anything repeats cyclically. Which computes the order. Lecture 9 - Fermat's Little Theorem - Math 453. Today we started by introducing a few methods for solving simultaneous congruences suggested by students in the class. We then finished our proof of Wilson's Theorem before moving on to introduce and prove the "other" theorem of Fermat: Fermat's Little Theorem (aka, flt). We saw several applications and corollaries of this result which made some modular computations really quite simple. We'll start by going back to the problem of solving simultaneous congruences. There were two new suggestions for solving these problems, and we'll provide a glimpse into both.

Solving by Inspection Sometimes you'll come across a system of congruences that looks something like this: How do you go about solving such a system? A sneakier version of this same technique can be used to solve the following system While it might not seem that you can "see" a solution to this equally, notice that these equations are the same as Now we can see that is a solution. Back Substitution Suppose you're given the system. Squaring 2-Digit Numbers. Let's see an example different from the ones at the index page.

Say, find 32². First add the last digit (2) to the number itself: 32 + 2 = 34. Multiply the sum by the first digit: Square the last digit: Append that square to the product just computed: 1024. If the square is a 2-digit number, append its last digit and carry the first digit to the last digit of the product. Why does this work? Let the number be N = 10a + b. So, to compute the square of N = 10a + b, first find N + b. In fact the method is not restricted to 2-digit numbers. a may have 2 or more digits as well. Find 215². 215 + 5 = 220. 5² = 25. . |Contact||Front page||Contents||Algebra||Math magic||Store| Frequently Asked Questions - The Flat Earth Wiki. Logo of the Flat Earth Society Welcome to the Flat Earth Society, and thank you for taking the time to go through this FAQ. It was created in light of the realization that for someone with a "round earth" background, the flat earth theory would appear, at first glance, to have some glaring holes.

This thread is designed to answer some of the questions that many round earthers raise when they first arrive. Please check this page before making your first threads in the forums, as it may contain the answers to the questions on your mind. Some of the questions here have multiple answers due to differing views of flat earth theory among some of our members. General Information The United Nations emblem closely resembles the Flat Earth map. Is this site a joke? This site is not a joke. What do all of these acronyms mean? Here is a link to flat earth Terminology! What evidence do you have? The evidence for a flat earth is derived from many different facets of science and philosophy. Russell's Paradox | Brilliant Math & Science Wiki. Fermat's little theorem. Examples Using Euler's Theorem - Mathonline.

Truth Tellers and Liars Warmup Practice Problems Online. Permutations | Brilliant Math & Science Wiki.