Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

What does this rebus puzzle means ?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

What kind of band never plays music?

What goes through cities and fields, but never moves?

What is more useful when it is broken?

While handling a project, the landscaper is asked by the owner of the mansion that he wants four trees in front of his mansion that are exactly equidistant from each other.

How will he do it?

Why is Saturday stronger than Monday?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

Can you solve the rebus below?