what does the below math rebus puzzle mean?

Three brothers Jacob, John, and James live in Mexico City. The product of the ages of these brothers is 175. Jacob and John are twins. How old is James?

What number should come in place of the question mark below?

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?

What does this rebus picture identify?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Who has married many women but was never married?

An explorer goes on an exposition in the jungle. He sets up camp in the middle of the jungle. The next morning he sees something with a head and a tail, but he is not afraid. What did he see in his bag?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?