Question

a dealer sells a toy for rupees 21 and loses as much percent as the cost price of the toy . what is the cost price of toy?

Answer 1

Answer:

Cost price = Rs 70

or

Cost price = Rs 30

Step-by-step explanation:

Let the cost price = C

Selling price = Rs 21

Percentage Loss = ( $\frac{C-21}{C}$ ) X 100%

but percentage loss = Cost price = C

=>  ( $\frac{C-21}{C}$ ) X 100 = C

on cross multiplication

$C^{2}$ = 100C - 2100

=>   $C^{2}$ - 100C - 2100 = 0

=>    C² - 70C - 30C - 2100 = 0

=>    ( C - 70 )( C - 30 ) = 0

=>     C = 70   or    C = 30

⇒  Cost price = Rs 70  or   Rs 30