Audrey is 7 years older than Heracles. In 3 years, Audrey will be twice as old as Heracles is now. How old is Heracles now? Give the rationale and then the answer.
Let's think step by step. Since Audrey is older than Heracles by 7 years, in 3 years he will be 10 years older than Heracles' current age. In 3 years he will be double Heracles' current age 10 * 2 = 20. Heracles is 10.. The answer is: 10.

Andy works in the pro shop at a tennis resort, where he earns $9 an hour. In addition to this, he gets paid $15 for each racquet he restrings, $10 for changing out the grommets on a racquet, and $1 for painting a stencil on the racquet strings. How much does he earn (before taxes) during an 8-hour shift if he strings 7 racquets, changes 2 sets of grommets, and paints 5 stencils? Give the rationale and then the answer.
Let's think step by step. Andy works 8 hours, so he earns a wage of 8 hours * $9 per hour = $72 just for working there. During that time, he restrings 7 racquets, so he earns 7 racquets * $15 per racquet = $105 from stringing. He also changed the grommets in 2 of those racquets, so he earned 2 grommet jobs * $10 per grommet job = $20 from changing grommets. And he stenciled 5 racquets, so he earned 5 stencil jobs * $1 per stencil job = $5 for stenciling. In total, Andy earned $72 + $105 + $20 + 5 = $202 for the day.. The answer is: 202.

In Mary's class, there are 25 students. Their teacher told them they could pay $50 each to finance a big science project that they and their society would benefit greatly from. They all paid the full amount except for 4 students, who paid half. How much was the class able to gather together? Give the rationale and then the answer.
Let's think step by step. The original amount is $50 so half is $50 / 2 = $25. 4 students paid half ($25) for a total of 4 * $25 = $100. There are 25 - 4 = 21 students left. 21 students paid the full amount ($50) for a total of 21 * $50 = $1050. They were able to gather a total of $100 + $1050 = $1150.. The answer is: 1150.