Answer: 3 dollars is saved on 9 bars
Explanation:
Original price of one bar soap is $2
Original cost of 3 bars would be 2×3 = $6
But it was sold at a rate of 3 bars for $5. Amount of money saved on 3 bars would be 6 - 5 = $1
If another 3 bars are bought for $5, the amount saved will be $1 again.
If 3 extra bars are bought for $5, the amount saved will be $1
Total number of bars bought is 3 + 3 + 3 = 9
Total amount saved = 1 + 1 + 1 = $3
Checking,
3 bars = $5
9 bars = (9×5)/3 = $15
Originally, 9 bars = 9×2 =$18
Amount saved = 18 - 15 = $3