Question

Five years back two friends age was in the ratio 5 : 1 and 30 years hence the ratio would be
10:9. Find the age of the younger friend after five years hence.
(a) 11 years
(b) 12 years
(c) 14 years
(d) 15 years​

Answer 1

Answer:

(a) 11years

Step-by-step explanation:

let present ages are x and y

before 5years,

=> x-5 : y-5 = 5:1

=> (x-5)/(y-5) = 5/1

=> x-5= 5y-25

=> x-5y= -20.............(1)

similarly after 30 years,

(x+30)/(y+30) = 10/9

=> 9x+270= 10y+300

=> 9x-10y= 30...................(2)

from (1) and (2)

7x= 70=> x= 10 years

again, 10-5y= -20

5y= 30

y= 6 years

thus age of younger friend after 5 years

= 6+5= 11 years , option (a) is correct.

.