If cost price = Rs 400 and selling price = Rs 500, profit% =

Given: cost price = Rs 400 and selling price = Rs 500

To find: We have to find the profit percentage.

Solution: 

Given that:

Cost price (CP) = ₹ 400

Selling price (SP) = ₹ 500

Now,

Profit = SP $-$ CP

Profit = ₹ 500 $-$ ₹ 400

Profit = ₹ 100

So,

$ Profit\ \%\ =\ \frac{Profit}{CP} \ \times \ 100\ \ \%\ $ 

$ Profit\ \%\ =\ \frac{100}{400} \ \times \ 100\ \ \%\ $ 

$ Profit\ \%\ =\ \frac{1}{4} \ \times \ 100\ \ \%\ $ 

$Profit\ \%\ = 25\%$.