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)