Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

Which tank will fill first?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

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?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

A man wants to cross the pit of fire which is 25 feet in length and he has 2 planks(fire resistant) 19 feet in length. How can he cross the pit of fire alive?

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13

A car meter reading shows 72927 miles a palindromic number.
what is the minimum number of miles you would need to travel to see another palindromic number on the car meter reading?

How many times can you subtract the number two from the number fifty?