Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?

A mules travels the same distance daily.
I noticed that two of his legs travels 10km and the remaining two travels 12km.
Obviously two mules legs cannot be a 2km ahead of the other 2.

The mules is perfectly normal. So how come this be true ?

What has one letter and starts with an E?

Solve the puzzle by telling what does below picture means.

John was driving a bus and got stuck when passing through an underpass. Then came Jacob with a needle and got the bus out of the underpass.

What did the boy do?

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?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag

You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"