Mensah is 5 years old and joyce is thrice as old as mensah. In how many years will joyce be twice as old as Mensah?

A.

3 years

B.

10 years

C.

5 years

D.

15 years

Correct answer is C

Mensah’s age is 5. Thus,

Joyce’s age is 15 (5*3=15)

The difference between their ages is 10 (15–5=10)

As we ought to find how many years Joyce’s age will be twice of Mensah’s age, we should write down the following :

15+X=2*(5+X)

15+X=10+2X lets add (-10-X) to both sides of the equation and

15+X-10-X = 10+2X-10-X

5=X —-> X=5

After 5 years Joyce’s age will be 20 (15+5=20)

After 5 years Mensah’s age will be 10 (5+5=10)

After 5 years Joyce will be twice as old as Mensah (10*2=20)