There are 20 students in the orchestra and twice that number in the band. There are 12 boys and 16 girls in the choir. If each student only participates in one group, how many students, in total, are there in the orchestra, the band, and the choir?
Let's think: There are 20 x 2 = 40 students in the band. There are 12 + 16 = 28 students in the choir. In total there are 20 + 40 + 28 = 88 students.. The answer is: 88.

Jenny is older than Charlie by five years, while Charlie is older than Bobby by three years. How old will Charlie be when Jenny becomes twice as old as Bobby?
Let's think: Jenny is older than Charlie by 5 years who is older than Bobby by 3 years, so Jenny is older than Bobby by 5 + 3 = 8 years. Jenny will be twice as old as Bobby when he is 8 * 2 = 16 years old. Jenny is 5 years older than Charlie so when Jenny is 16, Charlie will be 16 - 5 = 11 years old.. The answer is: 11.

Frank spent 1/5 of his money to buy groceries. He then spent 1/4 of the remaining money to buy a magazine. If he had $360 left in his wallet, how much money did he have at first?
Let's think: Let X be the money Frank had originally. Frank spent 1 / 5 * X on groceries. Frank spent 1 / 4 * (X - 1 / 5 * X) on a magazine. Frank has X - 1 / 5 * X - 1 / 4 * (X - 1 / 5 * X) = $360 left in his wallet. Multiplying through the parentheses, we get X - 1 / 5 * X - 1 / 4 * X + 1 / 20 * X = $360. Combining like terms, we get 12 / 20 * X = $360. Dividing both sides by 12 / 20, we get X = $600.. The answer is: 600.

Martin owns a farm with hens. 10 hens do lay 80 eggs in 10 days. Martin decided to buy 15 more hens. How many eggs will all hens lay in 15 days?
Let's think:
If 10 hens lay 80 eggs, then 1 hen lays 80 / 10 = 8 eggs in 10 days. That means one hen is laying 8 / 2 = 4 eggs in 5 days. So in 15 days, 1 hen will lay 3 times more eggs, so 4 * 3 = 12 eggs. All hens in total will then lay 25 * 12 = 300 eggs in 15 days.. The answer is: 300.