Transform the word THINK into BRAIN while changing only one letter at a time in a manner that each of the word in the process is a real word!!!

Before the start of the car race, John and Jacob have the same amount of fuel in their car. With this fuel, John can drive for 4 hours while Jacob can drive five hours.
After a time they realize that the amount of fuel left in John's car is 1/4th of the fuel in Jacob's.

For how long they are racing?

Solve below rebus puzzle?

Can you move 2 matchsticks to form four equal sized squares.

In the image given, you can find several triangles. Can you count them all?

1 + 9 + 8 = ?
considering, 28 + 8 + 92 = 10

What has to be broken before you can use it?

John was piloting a plane behind a car but was never able to overtake it. Why?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?