The C.P of 18 oranges is the same as the S.P of 15 oranges.Find the percentage gain?5%10%15%20%

Let's solve this step by step:

Step 1: Assume the cost price (C.P) of one orange is $1. Therefore, the cost price of 18 oranges would be$18.

Step 2: According to the problem, the selling price (S.P) of 15 oranges is also $18. Therefore, the selling price of one orange would be$18/15 = $1.2.

Step 3: The gain is calculated by subtracting the cost price from the selling price. So, the gain for one orange would be $1.2 -$1 = $0.2.

Step 4: The percentage gain is calculated by dividing the gain by the cost price and then multiplying the result by 100. So, the percentage gain would be ($0.2/$1)*100 = 20%.

So, the percentage gain is 20%.