Olga has an aquarium with fish in 5 different colors. There are 12 yellow ones, half as many blue ones, and twice as many green ones as yellow ones. How many fish does Olga have in her aquarium?
Let's think: Olga has half as many blue fish as yellow ones, which means 12 * 0.5 = 6 blue fish. Green fish are twice as many as yellow ones, so in total there are 12 * 2 = 24 green fish. So all the fish sum up to 12 + 6 + 24 = 42.. The answer is: 42.

Alyssa, Keely, and Kendall ordered 100 chicken nuggets from a fast-food restaurant. Keely and Kendall each ate twice as many as Alyssa. How many did Alyssa eat?
Let's think: To figure out this problem we need to turn it into an equation. Let’s make A the number of nuggets Alyssa ate. We know all three girls ate 100 nuggets total, so 100 nuggets = A (how many Alyssa ate) + 2A (how many Keely ate) + 3A (how many Kendall ate) or 100 = A + 2A + 3A which is 100 = 5A. Then we will divide each side by 5 to figure out how many nuggets Alyssa ate, 100 / 5 = 5A / 5 or 20 = A.. The answer is: 20.

Jonas is a book collector. He has so many books he is converting his third bedroom into a library. This room has 400 square feet of space. He plans to put several bookshelves in the room and each bookshelf takes up 80 square feet of space. If he reserves 160 square feet of space to use for a desk and some walking space, how many shelves can he put in the room?
Let's think: If he reserves 160 sq. ft. of space for a desk and some walking space, then he will have 400 - 160 = 240 sq. ft. of space remaining. If each bookshelf takes up 80 sq. ft. of space, then 240 sq ft can contain 240 / 80 = 3 bookshelves.. The answer is: 3.

Natasha has 3 times as much money as Carla, and Carla has twice as much money as Cosima. If Natasha has $60, and the three decide to buy goods worth the total amount they have and sell the goods at 7/5 of the buying price, how much profit would they make?
Let's think:
If Natasha has $60, which is 3 times as much money as Carla, Carla has $60 / 3 = $20. Together, Carla and Natasha have $20 + $60 = $80. Carla has twice as much money as Cosima, meaning Cosima has $20 / 2 = $10. Combined, the three have $10 + $80 = $90. If they buy goods with the amount they have and sell at 7 / 5 of the buying price, the total amount of money they will get from selling the goods is 7 / 5 * 90 = $126. If they earn $126 from the sale of the goods they bought with the money they had, their profit is $126 - $90 = $36.. The answer is: 36.