what does the below math rebus puzzle mean?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

Replace the question mark with the correct number below.

When is the top of a mountain similar to a savings account?

Which country gets ill every time?

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

Can you decipher the following common phrase?

T M C
A U O
H S M
W T E