Hello

This sum should take you no more than 5 seconds if you see the Magic with the numbers

The ratio increases from 5:6 to 6:7 .. means one on each side... In this case, how much time is past gives us the answer.

See, after 7 years, ratio increases from 5:6 to 6:7, means each 1 part of the ratio is 7 years itself!

Hence X's age is 6 X 7 = 42

I hope you Understood

Leave me a comment otherwise!