Question: There are currently 3 red balls, 11 blue balls, and 25 green balls in the store. Red balls cost $9, Blue balls cost $5 and green balls cost $3. How much will the store have received after all the balls are sold?
Can you solve this problem?
Answer: 
For the red balls, 3 balls * $9/ball = $27.
For the blue balls, 11 balls * $5/ball = $55.
For the green balls, 25 balls * $3/ball = $75.
For all balls, $27 + $55 + $75 = $157.