Question

Rahul bought a certain number of comics for rupees 300. If he had paid rupees10 more for each comic then he would have got comic less for same price . whats price of each comic

Answer 1

Let number of comic books be x
Let cost of each comic book be y

From question xy=300...(1)

Give that (y+10)(x-1)=300

xy-y+10x-10=300
300-y+10x-10=300
10x+10=y....(2)
Substitute (2) in (1)
10x^2+10x-300=0
x^2+x-30=0
x^2-6x+5x-30=0
x(x-6)+5(x-6)=0
x-6=0 and x+5=0
Therefore x=6
So y=300/6
y=50

Hope it helps