A number of light bulbs were purchased to illuminate a house. However, only 3/5 of them were needed and 72 leftover light bulbs were returned. If only 70% of the cost of those returned, or Rs. 11088, was reimbursed, how much money was spent on illuminating the house?
Bulbs used=3/5 .'. Bulbs returned=2/5
Let total bulbs=x, then (2/5)*x=72 ⇒ x=180
We know that Rs. 11088 represents 70% of the cost of 72 bulbs
.'. Full cost of 72 bulbs=(100/70)*11088=15840
Cost per bulb=15840/72=220
And cost which was not recovered=15840-11088=4752
Total cost = Cost(108 used bulbs) + Cost not recovered = 108*220 + 4752 = 28512 Rs.
There will be a mathematics in each and every problem you solve.
Jyothish K R
Language is remarkable, except under the extreme constraints of mathematics and logic, it never can talk only about what it's supposed to talk about but is always spreading around.