Question

Today is my birthday! Four-fifths of my current age is greater than three-quarters of my age one year from now.

Given that my age is an integer number of years, what is the smallest my age could be?

Answer 1

1/5 = 0.2
1/4 = 0.25
0.8x > 0.75(x + 1)
0.8x> 0.75x + 1
- 0.75x
0.05x > 1
÷ 0.05
x > 20
So because x (their current age) can't equal 20, the smallest value you can have is 21, which is your answer. Let me know if you have any questions, hope this helps :)