In 10 years, A will be twice as old as B was 10 years ago. If A is now 9 years older than B, then the present age of B is
A
19 years
B
29 years
C
39 years
D
49 years
Correct Answer: 39 years
Let, B's present age is x year & 10 years ago he was (x-10) After 10 years, A= 2((x-10), B= (x+10)Now, 2(x+10)-(x+10)=9Or, x=39 years.