0Mahashtra Board X std Algebra (year 2020)
A dealer sells a toy for Rs 24 and gains as much percent as the cost price of the toy.
Find the cost price of the toy.
Solution:
SP selling price
CP cost price
p profit percentage
SP= CP(1+p%)
Let CP = Rs x
profit percentage = x
SP =Rs 24 (given)
24 = x(1+x%)
24= x(1+(x/100))
24= x(100+x)/100
2400= 100x+x^2
x^2+100x-2400=0
Quad. Eqn.
Factorising:
x^2+120x-20x+2400=0
(x-20)(x+120)=0
x=20 or x=-120 ( negative price not applicable)
Ans : cost price = Rs 20.
Checking answer
SP=CP(1+p%)
SP=20(1+20%)
SP=20(1.2)=24
SP =Rs 24
Answer checked.
