Profit and loss 35 -10th grade

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If there is a profit of 20% calculated on selling price, what
is the percentage of profit calculated on cost price?

Solution: Let the selling price = $100

So profit = ${100 * (20/100)} = $20

So the cost price = $(100 – 20) = $80

On $80 profit is $20

So, on $1 profit is $(20/80)

So, on $100 profit is ${(20/80) * 100} = $25

So, the required rate of profit = 25%