Question

In March rohan's monthly expenditure was90% of his monthly income. His monthly income increased by 30% and his monthly expenditure increased by 20% when compared to the previous month. Find the percentage increase in his monthly savings.

Answer 1

Let income=x
expenditure =90x/100=9/10x
savings=income-expenditure=x-9x/10
=x/10
New income=x+30x/100=13x/10
New expenditure=9x/10 ×120/100
=54x/50=27x/25
New savings=13x/10-27x/25=(65x-54x)/50=11x/50
increase in savings=11x/50-x/10=(11x-5x)/50=6x/50=3x/25
savings percentage= increase / initial*100=(3x/25)/1x/10*100
=3x/25*10/x*100=120percent