Can someone help with the algebra word problem?

Question

Derek is 70 and his granddaughter Vanessa is 5. In how many years will Vanessa be 1/6 Derek's age.

An explanation is appreciated.

Answer

When he's 78 she will be 13. So it's 8 years from now.

Answer

Derek is 70, Vanessa is 5. So in x years Derek is (70 + x) and Vanessa is (5 + x).
The condition is that Derek is then 6 times older than Vanessa. 

70 + x = (5 + x)*6
70 + x = 30 + 6x  | -30 -x
5x = 40
x = 8.

Can someone help with the algebra word problem?

Answers (2)