Question

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

Answer 1

Explanation:

Let Cyril = C

Let Alex = A

A + C = 50 (1)

A+5 = 4*C (2)

Solve (1) for A

A + C = 50 Solve for A

A + C-C = 50 - C

A = 50 - C

Substitute A into (2)

50 - C + 5 = 4C Add C to Both sides

50 + 5 = 4C + C Combine

55 = 5C Divide by 5

55/5 = 5C/5

C = 11

A + C = 50 Substitute for C

A + 11 = 50 Subtract 11 from both sides

A = 50 - 11

A = 39