### SAT Prep Class: Calculating Percents

Check out Bas Rutten's Liver Shot on MMA Surge: http://bit.ly/MMASurgeEp1 SAT Prep Question #6 Question: 25% of 48 is 80% of what number? This problem may appear difficult at first, but just remember that it's a regular percentage problem. Once you turn the word problem sentence into an equation, it will be easier to solve.? Solve the Problem 1. First turn the word problem into an equation. Write the percents at decimals. Change "of" into multiplication. "Is" becomes "=". Mark the unknown number by an "x." 2. The problem should now look like this:? (.25)(48)=(.80)(x) 3. Now you can solve the problem with regular arithmetic. The easiest way to solve it without a calculator is by turning the decimals into fractions. This will make your equation look like this:? (1/4)(48)=(80/100)(x) 80/100 can be reduced to 8/10 and then reduced again to 4/5. The final equation to solve will be:? (1/4)(48)=(4/5)(x) 4. Multiply the fractions to solve for "x."? 1 ?x ?48? = ?4 ?x X 4 ? ? ? 1 ? ? ? 5 ? ? 1 Cross cancel the 4 and 48 to get 12/1. Your equation is now 12=(4/5)x.? 5. Multiply both sides of the equation by 5/4 to eliminate the fraction. 4/5 times 5/4 equals 1, so the right side of the equation will be 1x. On the left side, 12 times 5/4 is 15. The equation will now be 15=x.? Therefore, the answer to the problem is 15. Read more by visiting our page at: http://www.mahalo.com/courses/sat-math-prep/practice-questions/calculating-percents/

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