Catriona has 8 goldfish in her aquarium. She has 4 more angelfish than goldfish. Also, she has twice as many guppies as angelfish. How many fish does Catriona have in her aquarium?
Let's think: Catriona has 8 + 4 = 12 angelfish. She also has 12 x 2 = 24 guppies. Thus, she has 8 + 12 + 24 = 44 fish in her aquarium.. The answer is: 44.

Isabel has some money in her piggy bank. She spent half the amount and bought a toy. She then spent half of the remaining money and bought her brother a book. If she has $51 left, how much money, in dollars, did she have at first?
Let's think: After buying the toy, Isabel has 51 * 2 = 102 dollars left. Isabel had 102 * 2 = 204 dollars at first.. The answer is: 204.

A farmer has twice as many pigs as cows, and 4 more cows than goats. If the farmer has 56 animals total, how many goats does he have?
Let's think: Let x be the number of goats. Cows:4 + x. Pigs:2(4 + x) = 8 + 2x. Total:x + 4 + x + 8 + 2x = 56. 4x + 12 = 56. 4x = 44. x = 11 goats.. The answer is: 11.

A pharmacy is buying enough tubs for them to make their prescriptions this week. They already have 20 tubs left in storage but they need a total of 100 tubs for the week. Of the tubs they still need to buy, they buy a quarter from a new vendor then decide to go to their usual vendor for the rest. How many tubs is the pharmacy going to buy from the usual vendor?
Let's think:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
They already have 20 tubs in storage, so they only need to buy 100 needed tubs - 20 tubs in storage = 80 tubs. From the new vendor, they buy 80 tubs / 4 = 20 tubs. They now have a total of 20 + 20 = 40 tubs. They are therefore going to buy 100 needed tubs - 40 owned tubs = 60 tubs from the usual vendor.. The answer is: 60.