Question

The sum of the ages of husband and wife at present is 100. Ten years ago the ratio of their ages was 9:7. What is the age of the husband?

A) 45 years B) 55 years C) 65 years D) 40 years

Answer 1

Answer:

let the age of husband = x

let the age of wife = y

x + y = 100 ------- (1)

(x-10) / (y -10) = 9/7

7x-70 = 9y-90

7x - 9y = -90+70

7x - 9y = -20 --------- (2)

x + y = 100 * 7

7x-9y = -20 * 1

7x+7y= 700

7x-9y= -20

(-) (+)   (+)

16y= 720

y = 720 / 16

y = 45

NOW BY ELIMINATION METHOD WE GET VALUE OF X

Let take the eq. 1

x + y = 100

x+ 45= 100

x= 100-45

x= 55

NOW WE GET THE VALUE OF X= 55 YEARS

HOPE THIS HELP U