Ratio & Proportion Questions

Question

The ratio of the ages of X and Y is 3 : 7. The ratio of the ages of X and Z is 5 : 14. Find the ratio of the ages Y and Z ?

Answer (C): 5 : 6

Explanation:

Ratio of the ages of X and Y = 3 : 7 = 15 : 35

Ratio of the ages of X and Z = 5 : 14 = 15 : 42

Ratio of the ages of Y and Z = 35 : 42 = 5 : 6

Let the number of boys be x

Number of girls = x + 16

x + x + 16 = 40

⇒12

Average weight of class = 47.7

Let the average weight of the boys be y

Total weight of class = y × 12 + 45 × 28

y × 12 + 45 × 28 = 47.7 × 40

12y = 648

y = 54