Question

Rajan earns Rs. 16000 /month. He spend 3/1 of the income on rent. 1/4 on food and spend 5/21 on children... How much money is still left with him

Answer 1

Let's first see what information we have,
Total Income = Rs.16000/month
Amount spent on rent = 1/3 of 16000
Amount spent on food= 1/4 of 16000
Amount spent on children = 5/21 of 16000
Thus we can take 16000 as common and add all 3 fractions,
1/3 + 1/4 + 5/21 = 48/84 = 4/7
Thus amount left = (7/7 - 4/7 )*16000
= 3/7 *16000
=6857.142857 (the decimal part is reccuring and non terminating.)
Hope this helped you!