Question

find cost price if s.p =₹21 and gain =5%

Answer 1

hola ,

CP=100/100+gain%*SP/1
=100/100+5*21/1
100/105*21/1
100/5*1/1
20

hence CP is RS 20.

hope it helps you
if any query please ask

Answer 2

Answer:

The cost price is ₹ 20.

Step-by-step explanation:

We have to find the cost price.

Let us assume, Cost price is 100 %

As gain is 5% , selling price is: (100 + 5) % = 105 %

Selling price is given ₹21.

Hence, 105 % is ₹ 21

So, 1 % is: ₹ 21/105

And 100 % is: ₹ (21/105) x 100 = ₹ 20

So the cost price is ₹ 20. (Answer)