The Little ant seems to be always confused. Do you know why?

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?

By using all numbers, i.e. 123456789 and subtraction/addition, operators number 100 can be formed in many ways.
Example: 98 + 7 + 6 - 5 - 4 - 3 + 2 - 1 = 100

But if we add a condition use of the number 32 is a must. Then there are limited solutions.
One of such solution is: 9 - 8 + 76 + 54 - 32 + 1 = 100

Can you tell me any other solution?

Which city is three-fifths chick two third cat and 50% goat?

What is next number in the pattern below:

131 517 192 123 ?

Can you count the number of triangles in the picture below?

It's pretty hard to give up.
If you remove a part of it, you will be left with a bit.
Even if you remove another part, the bit still remains.
Remove one more and it still remains.

What is it?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

What has many teeth, but cannot bite?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?