Question

A family bought 5 litres of oil on the first day of the month .If 5/4 litres of oil was left over at the end of the month, then what was the family's consumption of cooking oil during that month?​

Answer 1

Total oil bought = 5 litres (5/1)

Total oil used = 5/4 litres

Let oil left = x litres

5/1 - 5/4 = x

LCM of 1 and 4 = 4

5/1 = 5/1 x 4/4 = 20/1

5/4 = 5/4 x 1/1 = 5/4

Oil left = 20/ - 5/4

= 15/4 litres = 3 whole 3/4 litres of oil

So, 3 whole 3/4 litres of cooking oil is left.

Hope it helps..