Question

$\frac{2}{3}$ of a number is less than the original number by 10. The original number is

(a) 30
(b) 36
(c) 45
(d) 60

Answer 1

$\begin{array}{l}\left(\text{a}\right)30\\ \text{Let the original number be}x.\\ \mathrm{Then},\frac{2}{3}x=x-10\\ \Rightarrow 2x=3x-30\\ \Rightarrow 2x-3x=-30\\ \Rightarrow \cancel{-}x=\cancel{-}30\\ \Rightarrow x=30\\ \therefore \text{The required number is 3}0.\end{array}$