New SAT Math Workbook

New SAT Math Workbook

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

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: = ⋅ 100 = 2% 1500 150 50 Example: 12 is what percent of 72? Proportion Method x 12 = 100 72 72 x = 1200 Fraction Method 12 1 2 = = 16 % 72 6 3 2 %. If you have memorized the fractional equivalents 3 Time consuming long division is needed to find x = 16 of common percents, this method requires only a few seconds. Example: What percent of 72 is 16? Proportion Method x 16 = 100 72 72 x = 1600 2 x = 22 % 9 Fraction Method 16 2 200 2 = ⋅ 100 = = 22 % 72 9 9 9 www.petersons.com Percent 79 Exercise 4 Work out each problem. Circle the letter that appears before your answer. 1. 4 is what percent of 80? (A) 20 (B) 2 (C) 5 (D) .5 (E) 40 1 1 of 6 is what percent of of 60? 2 4 4. What percent of 48 is 48? (A) 1 (B) 10 (C) 100 (D) 48 (E) 0 What percent of y is x? (A) (B) (C) (D) (E) x y x 100 y xy 100 100 x y 100 y x 2. 5. (A) (B) (C) (D) (E) 3. 5 20 10 25 15 What percent of 96 is 12? (A) (B) (C) (D) (E) 16 8 1 3 1 2 2 3 37 8 12 1 2 www.petersons.com 80 Chapter 5 5. PERCENTS GREATER THAN 100 When the percentage involved in a problem is greater than 100, the same methods apply. Remember that 100% = 1 1; 200% = 2; 300% = 3 and so forth. Therefore 150% will be equal to 100% + 50% or 1 . Let us look at one 2 example of each previously discussed problem, using percents greater than 100. Example: Find 175% of 60 Proportion Method Decimal Method 60 175 x = 100 60 100 x = 10500 x = 105 Fraction Method × 1.75 300 4200 6000 105.00 3 1 ⋅ 60 4 15 7 ⋅ 60 = 105 4 Example: 80 is 125% of what number? Proportion Method 125 80 = 100 x 125 x = 8000 x = 64 Decimal Method 80 = 1.25 x 8000 = 125 x x = 64 Fraction Method 1 80 = 1 x 4 5 80 = x 4 320 = 5 x x = 64 Example: 40 is what percent of 30? Proportion Method x 40 = 100 30 30 x = 4000 1 x = 133 % 3 Fraction Method 40 4 1 1 = = 1 = 133 % 30 3 3 3 www.petersons.com Percent 81 Exercise 5 Work out each problem. Circle the letter that appears before your answer. 1. 36 is 150% of what number? (A) 24 (B) 54 (C) 26 (D) 12 (E) 48 What is 300% of 6? (A)...
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