Can the function t(n) have negative integers?

Due to a packaging error, 4 cans labeled diet soda were accidentally filled with regular soda and placed in a 12 pack carton of diet soda. two cans were randomly selected from this 12 pack. what is the probability that both cans were regular soda?

The difference of two numbers is 40. find the numbers if 0.3 parts of one number is equal to 37.5% of the other one.

Alakefront cottage that is 30 feet high casts a shadow on the water. how long is that shadow if a 16-foot-high truck parked nearby casts an 8-foot shadow?