Jerry works five days a week as a waiter and earns a variable amount of tips every night. The past four nights, he earned $20, $60, $15, and $40. How much does he need to earn tonight if he wants to make an average of $50 in tips per night?
Let's think: The total money Jerry needs to make for 5 days to get $50 per night is 5 nights * $50 / night = $250. His total earnings for the past four days is $20 + $60 + $15 + $40 = $135. So, Jerry needs to earn $250 - $135 = $115 in tips tonight.. The answer is: 115.

Brenda is a vet who needs to spay some cats and twice as many dogs. If she needs to spay 21 animals total today, how many cats does she need to spay?
Let's think: Let c be the number of cats Brenda needs to spay and d be the number of dogs. We know that c + d = 21 and d = 2c. Substituting the second equation into the first, we get c + 2c = 21. Combining like terms, we get 3c = 21. Dividing both sides by 3, we get c = 7.. The answer is: 7.

James has five huskies, two pitbulls and four golden retrievers, all female. They became pregnant and each golden retriever had two more pups than each husky. If the huskies and pitbulls had 3 pups each, How many more pups than adult dogs are there in total?
Let's think: There are 5 + 2 = 7 huskies and pitbulls. 7 huskies and pitbulls had 3 pups each for a total of 3 * 7 = 21 pups. Each golden retriever had 2 more pups each than the huskies who had 3 each so each golden retriever had 3 + 2 = 5 pups. 4 golden retrievers had 5 pups each for a total of 20 pups. There are a total of 21 + 20 = 41 pups. There are a total of 5 + 2 + 4 = 11 adult dogs. There are 41 - 11 = 30 more pups than adult dogs.. The answer is: 30.

Jamie knows that once she has any more than 32 ounces of liquid she has to use the bathroom, and her teacher said that no one can use the bathroom during the math test. She remembers that she had a cup of milk at lunch and a pint of grape juice at recess. How many ounces can she drink from her water bottle during the test before she'd have to go to the bathroom? (A cup equals 8 ounces and a pint equals 16 ounces.)
Let's think:
Jamie has had 24 ounces because 8 plus 16 equals 24. She can drink 8 ounces because 32 - 24 equals 8.. The answer is: 8.