Question

If list price of a toy is reduced by Rs.5,a person can buy 5 more toys for Rs.300.Find the original price of the toy.

Answer 1

lets the no of toys be x and price of each toy be y
now,in 1st situation
xy=300
x=300/y---------- (eq.1)

in 2nd situation,
(x+5)(y-5)=300
xy -5x +5y -25 =300
xy-5x +5y = 325
put eq.1

$\frac{300}{y}$ x y - 5 x300/y +5y =325
-1500/y + 5y = 25
-1500 + 5y$^{2}$ = 25 y
-1500 = 20y
y=1500/20
y=75
75x=300
x=300/75
x=4