The sum of ages of Sarpong and Quartey is 50 years. In five years time, the age of Quartey will be four times the age of Sarpong now. How old is each boy?

Question

The sum of ages of Sarpong and Quartey is 50 years. In five years time, the age of Quartey will be four times the age of Sarpong now. How old is each boy?

Answer 1

Here's what we know:

S + Q = 50

5 + Q = 4S

 

Let's try substitution. We can isolate Q by subtracting S to both sides:

Q = 50 - S

 

5 + (50 - S) = 4S

55 - S = 4S

55 = 5S

11 = S

 

Q = 50 - 11

Q = 39

 

Let's check our answer:

5 + 39 = 4 * 11

44 = 44