Question

By selling notebook for 22 rupees a shopkeeper gains 10%.The cost price of the book is

Answer 1

The book is sold at the cost of 22 rupees.

final price = fp.

gain = 10 %.

let cost price be cp.$[tex]we know gain percentage = \frac{fp - cp}{cp}*100$[/tex]

$gain percentage = \frac{22-cp}{cp}*100$

$10 = \frac{22-cp}{cp}*100.\\ \frac{cp}{22-cp}=10.\\ cp = 10*(22-cp).\\cp=220-10cp.\\cp+10cp=220.\\11cp=220.\\cp=\frac{220}{11}.\\ cp=20.$

therefore cost price of the book is 20 rupees.

Answer 2

Answer:

S.P. is ₹ 22

Profit in % = 10%

So,

Cost price = 100/(100+gain %) * selling price

= 100/(100+10)*22

= 100/110*22

= 2200/110

Cost price is ₹ 20