Question

Please I need help

A man spent two fifth of his salary on rent ,one-quater on food and one-eight on transport.What fraction does he have left? (a)³¹/40 (b)²³/⁴ (c)²¹/⁴⁰ (d)⁹/⁴⁰​

Answer 1

Hi! You just have to take his salary as a unity (one) and substract the fractions you are given. For example; lets say you have a cake (one) and then you eat 1/8 of it. You would be left with
`1-\frac{1}8}` of the original cake.

Explanation:

Salary:
`1`

Spent
`(2)/(5)` :
`1-(2)/(5)`

Spent
`(1)/(4)`:
`1-(2)/(5) -(1)/(4)`

Spent
`(1)/(8)`:
`1-(2)/(5) -(1)/(4) -(1)/(8)`

REMAINING:
`1-(2)/(5) -(1)/(4) -(1)/(8)`

Operate using LCM:
`(40-16-10-5)/(40) = (9)/(40)`

The answer is (d)