Problems of the Week - August 2 to August 8

Rewards for Problems of the week:

5 stars for the correct answer at your level; 10 stars for the next level; 20 stars for 2+ levels up.

Lower Elementary:

Question: An alligator starts life with 80 teeth. When an alligator tooth wears down or falls out, the alligator grows a new one. How many teeth has an alligator had in total if it has replaced each of its teeth 3 times?

Upper Elementary: 

Question: A frog croaks 1 time when a storm is 1 mile (5,280 feet) away. When the storm is half of a mile away, the frog croaks 2 times. When the storm is a third of a mile away, the frog croaks 3 times. How many feet away is the storm when the frog croaks 5 times?

Middle School: 

Question: Three loaves of stale bread is enough to feed 8 adult ducks or 16 ducklings. How many loaves of bread are needed to feed 6 adult ducks and 12 ducklings?

Algebra and Up:

Question: A heron is fishing in a pond that has 3 carp, 4 bass, and 5 trout. The heron catches the fish at random and swallows every fish it catches. What is the probability that the heron will catch a carp and then a trout?

Challenge problem to take home. 5 stars for the correct answer. 

Ethan's first day as a waiter isn't going too well — he completely forgot which of the four guests ordered which of the four different plates he's carrying. If at least one guest receives the meal they wanted, Ethan won't get into serious trouble.

In how many ways can he bring at least one meal to the correct person?