My current age is the age of my favourite book (which is 14 years old) plus one third of my age.

How old will I be when my favourite book is twice its current age?

Puzzle Copyright © Kevin Stone

workings
hint
answer
print

Share link: www.brainbashers.com/puzzle/znth

Hint

A little algebra might help.

Answer

I will be 35 in 14 years.

Reasoning

I am currently 21.

If x is my current age, then:

x = 14 + x

—

3

so

2x = 14

——

3

and

2x = 42

So

x = 21

I am currently 21 and my favourite book is currently 14 years old, when it is 28 years old (double its age) I will be 35.