[Question]: There are 5 houses on a street, and each of the first four houses has 3 gnomes in the garden. If there are a total of 20 gnomes on the street, how many gnomes does the fifth house have?
[Answer]: In the first four houses, there are a total of 4 houses * 3 gnomes = 12 gnomes. Therefore, the fifth house had 20 total gnomes 12 gnomes = 8 gnomes.
So the answer is 8.

[Question]: Utopia National Park hosted 30,000 elephants on Friday night. The next morning, there was a 4-hour elephant exodus out of the park, at a constant rate of 2,880 elephants/hour. Over the next 7-hour period, new elephants entered the park at a constant rate. If the final number of elephants in the park was 28,980, at what rate did the new elephants enter the park?
[Answer]: The Saturday morning exodus out of the park comprised 4 * 2880 = 11520 elephants. This means that after the exodus, the park was left with 30000 - 11520 = 18480 elephants. Since the final number of elephants was 28,980, the new elephants that entered were 28980 - 18480 = 10500. The rate at which the new elephants entered the park was therefore 10500 / 7 = 1500 elephants / hour.
So the answer is 1500.

[Question]: Ali keeps his bills in his wallet. He has 7 bills of 5 dollars and 1 bill of 10 dollars. How much money does he have in total?
[Answer]:
Ali has 7 * $5 = $35 from the seven 5 - dollar bills. So in total, he has $35 + $10 = $45.
So the answer is 45.