The present ages of three persons in proportions 4 : 7 : 5. Eight years ago, the sum of their ages was 56. Find their present ages (in years).
Answers: A) 8, 20, 28 B) 16, 28, 36 C) 20, 35, 25 D) 16, 28, 34 E) 16, 28, 33
Let their present ages be 4x, 7x and 5x years respectively.   Then, (4x - 8) + (7x - 8) + (5x - 8) = 56   16x = 5.   Their present ages are 4x = 20 years, 7x = 35 years and 5x = 25 years respectively.   Answer:20, 35, 25
<result>C</result>
The present ages of three persons in proportions 4 : 7 : 5. Eight years ago, the sum of their ages was 56. Find their present ages (in years).