New SAT Math Workbook

# 4 5 12 16 20 2 find the numerator of the 3 the

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: respectively, or 1.5 and 2, or 45 and 60, or an infinite number of other combinations. All we know is that the ratio of numerator to denominator will be 3 : 4. Therefore, the numerator may be represented by 3x and the denominator by 4x. The fraction is then repre3x sented by . 4x 3 Example: The value of a fraction is . If one is subtracted from the numerator and added to the denominator, 31 the value of the fraction is . Find the original fraction. 2 2 Solution: Represent the original fraction as 3x . If one is subtracted from the numerator and added to the denominator, the new fraction is 2 x − 1 . The value of this new fraction is 1 . 2x − 1 1 = 3x + 1 2 3x + 1 2 2x Cross multiply to eliminate fractions. 4 x − 2 = 3x + 1 x=3 The original fraction is 2x 6 , which is . 3x 9 www.petersons.com Problem Solving in Algebra 179 Exercise 5 Work out each problem. Circle the letter that appears before your answer. 1. A fraction is equivalent to 4 . If the numerator 5 4. is increased by 4 and the denominator is increased by 10, the value of the resulting fraction is (A) (B) (C) (D) (E) 2. 4 5 12 16 20 2 . Find the numerator of the 3 The denominator of a certain fraction is 5 more than the numerator. If 3 is added to both numerator and denominator, the value of the new fraction is 2 . Find the original fraction. (A) (B) (C) (D) (E) 3 8 4 9 11 16 12 17 7 12 3 original fraction. What number must be added to both the numerator and the denominator of the fraction 5 3 to give a fraction equal to ? 21 7 5. The denominator of a fraction is twice as large as the numerator. If 4 is added to both the numerator and denominator, the value of the fraction is (A) (B) (C) (D) (E) 6 10 12 14 16 5 . Find the denominator of the 8 (A) (B) (C) (D) (E) 3. 3 4 5 6 7 original fraction. 3 The value of a certain fraction is . If both the 5 numerator and denominator are increased by 5, the new fraction is equivalent to original fraction. (A) (B) (C) (D) (E) 3 5 6 10 9 15 12 20 15 25 7 . Find the 10 www.petersons.com 180 Chapter 12 6. MIXTURE PROBLEMS There are two kinds of mixture...
View Full Document

## This note was uploaded on 08/15/2010 for the course MATH a4d4 taught by Professor Colon during the Spring '10 term at Embry-Riddle FL/AZ.

Ask a homework question - tutors are online