Five less than three times the number of Doberman puppies plus the difference between the number of Doberman puppies and the number of Schnauzers is equal to 90. If the number of Doberman puppies is 20, how many Schnauzers are there? Give the rationale and then the answer.
Let's think step by step. Three times the number of Doberman puppies is 3 * 20 = 60. Five less than three times the number of Doberman puppies is 60 - 5 = 55. Let's say the number of Schnauzers is s. The difference between the number of Doberman puppies and the number of Schnauzers is s - 20. Five less than three times the number of Doberman puppies plus the difference between the number of Doberman puppies and the number of Schnauzers is equal to 90, meaning 55 + s - 20 = 90. The number of Schnauzers which is s + 55 - 20 = 90. This evaluates to s + 35 = 90. There are s = 55 Schnauzers.. The answer is: 55.

At the zoo, there are 5 different types of animals. Seeing each animal type takes around 6 minutes. How much time would it take to see each animal type if the zoo decided to import 4 new species? Give the rationale and then the answer.
Let's think step by step. If the zoo would decide to import 4 new species, there would be 5 + 4 = 9 species in total. This would mean, that seeing each type of animal would take 9 * 6 = 54 minutes.. The answer is: 54.

Amy's grandfather gave her $100 for her birthday. Amy bought 3 dolls, each of which cost $1. How much money does Amy have left? Give the rationale and then the answer.
Let's think step by step. The cost of the dolls is 3 $1 = $3. Amy has $100 $3 = $97 left.. The answer is: 97.