It takes Jennifer 20 minutes to groom each of her 2 long hair dachshunds. If she grooms her dogs every day, how many hours does she spend grooming her dogs in 30 days?
Let's think: She has 2 dogs and it takes 20 minutes to groom just 1 dog so it takes her 2 * 20 = 40 minutes per day to groom 2 dogs. In 30 days, she will have spent 30 * 40 = 1,200 minutes grooming her dogs. There are 60 minutes in an hour so she spends 1200 / 60 = 20 hours grooming her dogs.. The answer is: 20.

Beth is a scuba diver. She is excavating a sunken ship off the coast of a small Caribbean island and she must remain underwater for long periods. Her primary tank, which she wears when she first enters the water, has enough oxygen to allow her to stay underwater for 2 hours. She also has several 1-hour supplemental tanks that she takes with her as well as stores on the ocean floor so she can change tanks underwater without having to come up to the surface. She will need to be underwater for 8 hours. How many supplemental tanks will she need?
Let's think: For an 8 - hour dive, she will use her 2 - hour primary tanks and will need supplemental tanks for 8 - 2 = 6 additional hours. Since each supplemental tank holds 1 hour of oxygen, for 6 hours she will need 6 / 1 = 6 supplemental tanks.. The answer is: 6.

Gerald had 20 toy cars. He donated 1/4 of his toy cars to an orphanage. How many toy cars does Gerald have left?
Let's think: Gerald gave away 20 x 1 / 4 = 5 of his toy cars. Therefore, he is left with 20 - 5 = 15 toy cars.. The answer is: 15.

In a restaurant, the chef prepared 17 meals to sell for lunch. During lunch, he sold 12 meals. After lunch, the chef prepared another 5 meals for dinner. How many meals does the chef have for dinner, assuming he can use the remaining lunch meals as well?
Let's think:
The chef had 17 - 12 = 5 meals left after lunch. So, the chef has 5 + 5 = 10 meals for dinner.. The answer is: 10.