[Question]: Reginald is selling apples. He sells each apple for $1.25. He plans to use his profits to help repair his bike. His bike cost $80 and the repairs cost 25% of what his bike cost. After the repairs are paid for, 1/5 of the money he'd earned remains. How many apples did he sell?
[Answer]: The bike repairs cost $20 because 80 x .25 = 20. Call the amount he earns e. We know that e - 20 = 1 / 5e. Therefore 5e - 100 = e. Therefore, 4e = 100. Therefore, e = 25. Therefore, he sold 20 apples because 25 / 1.25 = 20.
So the answer is 20.

[Question]: Mrs. Young buys a 300 piece puzzle set for her three sons. She divides the pieces evenly to the three boys. Reyn can place 25 pieces into the puzzle picture. Rhys places twice as much as Reyn. Rory places three times as much as Reyn. Altogether, how many puzzle pieces are still left to be placed?
[Answer]: Each son receives 300 / 3 = 100 pieces. Rhys places 25 x 2 = 50 pieces. Rory places 25 x 3 = 75 pieces. All three boys place 25 + 50 + 75 = 150 pieces. The boys have not placed 300 - 150 = 150 pieces.
So the answer is 150.

[Question]: John receives $100 from his uncle and gives his sister Jenna 1/4 of that money. He goes and buys groceries worth $40. How much money does John have remaining?
[Answer]:
When John gives his sister 1 / 4 of his money, he parts with 1 / 4 * 100 = 25 dollars. Johns remains with 100 - 25 = 75 dollars. When he buys groceries worth $40, he remains with 75 - 40 = 35 dollars.
So the answer is 35.