1.  The present ages of two persons are 36 and 50 yr, respectively. If after n yr the ratio of their ages will be 3 : 4, then the value of n is :
A. 3
B. 4
C. 7
D. 6

Answer: Option D

Explanation:

According to the question,

Then, 36 + n = 3
50+ n 4

144 + 4n = 150 + 3n

n = 6