Number System
A shopkeeper purchased 200 bulbs for Rs. 10 each. However, 5 bulbs were fused and had to be thrown away. The remaining were sold at Rs. 12 each. What will be percentage profit?
Let the number be 10x + y.∴ x + y = 12 ...........(i)10x + y - (10x + x) = 18or 10x + y - 10y - x = 18or 9x - 9y = 18∴ x - y = 2From (i) and (ii), x = 7, y = 5∴ Number = 75
EXAMIANS