New SAT Math Workbook Episode 1 part 5

Tham khảo tài liệu 'new sat math workbook episode 1 part 5', ngoại ngữ, ngữ pháp tiếng anh phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Variation 65 Exercise 1 1. C 1 ft. 4 in. 16 in. 1 yd. 36 in. 16 _4 36 9 2. D The team won 25 games and lost 15. 25_ 5 15 3 3. B a d Cross multiply. Divide by a. ad bc bc d a 4. E 32 x 1 28 8 32x 32 224 32x 192 x 6 5. A 9 y - 1 2y 3 9y - 9 6y 3y 9 y 3 Exercise 2 1. D We compare books with cents. D dollars is equivalent to 100D cents. 3 _ 8 100D x 3x 800D 800D x 3 2. B We compare inches to miles. 1 21 10 x 2 x 22 2 x 45 Cross multiply. Multiply by 2. 3. C We compare cents to miles. 8 _ x 5 115 5x 920 Cross multiply. x 4. D We compare gallons to miles. 20 x 425 1000 425x 20 000 Cross multiply. To avoid large numbers divide by 25. 17x 800 x 471 17 5. A We compare planes to passengers. r _ x p m px rm rm x p Cross multiply. Divide by p. com 66 Chapter 4 Exercise 3 Exercise 4 1. B Number of machines times hours needed remains constant. 8 6 5 x 48 5x x 5 9J 2. C Number of children times days remains constant. 90 4 80 x 80x 360 x 4I 2 3. B Diameter times speed remains constant. 15 200 x 150 3000 150x x 20 4. E Weight times distance from fulcrum remains constant. 80 x 60 8 80x 480 x 6 5. A Number of teeth times speed remains constant. 20 200 x 250 250x 4000 x 16 1. A The more chickens the fewer days. This is inverse. 30 4 40 x 40x 120 x 3 2. A The more cases the more cents. This is direct. We compare cents with cans. Inp cases there will be 12p cans. c x 1 12p x 12cp 3. C The fewer boys the more days. This is inverse. m d m - 2 x md ----r x m-2 4. E The less butter the less sugar. This is direct. Change 4 lb. to 12 oz. 12_ 10 18 x 12x 180 x 15 5. B The more kilometers the more miles. This is direct. 3 _ x 100 x 300 18x 3000 x 166 3 Variation 67 Retest 1. B 3x 12 8 x 7 36x 8x 56 28x 56 x 2 2. D 10 Cross multiply. x 15 30 10 x x 3 3. B We compare inches to miles. 1 31 Cross multiply. Multiply by 2. 20 x x 65 2 x 130 4. E We compare dollars to months. 12 000 _ x 5 12 Cross multiply. 144 000 5x x 28 800 5. D We compare pencils to .