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?
3 years
10 years
5 years
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)