## ASVAB Arithmetic Reasoning Practice Test 153375

 Questions 5 Topics Adding & Subtracting Fractions, Factorials, Multiplying & Dividing Exponents, Multiplying & Dividing Fractions, Percentages

#### Study Guide

Fractions must share a common denominator in order to be added or subtracted. The common denominator is the least common multiple of all the denominators.

###### Factorials

A factorial has the form n! and is the product of the integer (n) and all the positive integers below it. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120.

###### Multiplying & Dividing Exponents

To multiply terms with the same base, multiply the coefficients and add the exponents. To divide terms with the same base, divide the coefficients and subtract the exponents. For example, 3x2 x 2x2 = 6x4 and $${8x^5 \over 4x^2}$$ = 2x(5-2) = 2x3.

###### Multiplying & Dividing Fractions

To multiply fractions, multiply the numerators together and then multiply the denominators together. To divide fractions, invert the second fraction (get the reciprocal) and multiply it by the first.

###### Percentages

Percentages are ratios of an amount compared to 100. The percent change of an old to new value is equal to 100% x $${ new - old \over old }$$.