Question

The ages of A,B,C are ratio 7:9:12 and their sum of ages 168 find the ages of A,B, and C also the of A after 7 year

Answer 1

We have:

a : b : c = 7 : 9 : 12

a + b + c = 168

-> $\frac{a}{7} = \frac{b}{9} = \frac{c}{12} = \frac{a+b+c}{7+9+12} = \frac{168}{28}  = 6$

-> a = 6 x 7 = 42

   b = 6 x 9 = 54

   c = 6 x 12 = 72

Ages of A, B, C after 7 years:

A = 42 + 7 = 49

B = 54 + 7 = 64

C = 72 + 7 = 79

Answer 2

Let x be the common multiple of 7:9:12.

so it will be, 7x,9x and 12x.

Hence , 7x+9x+12x=168

so, 28x=168

x= 168÷28

hence; x=6

A= 7x=7×6=42

B= 9x=9×6=54

C=12x=12×4=48.

Age of A after 7years is 49.

Age of B is 54 years old.

Age of C is 48 years.