Baseball bat and ball cost $100. If the bat cost $99 more than the ball, what is the cost of each?

If a shopkeeper can only place the weights on one side of the common balance. For example, if he has weights 1 and 3 then he can measure 1, 3 and 4 only. Now the question is how many minimum weights and names of the weights you will need to measure all weights from 1 to 1000? This is a fairly simple problem and very easy to prove also.

You bought me for dinner but never eat me. What am I?

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

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.

A red house is made out of red bricks. A yellow house is made out of yellow bricks. And, a blue house is made out of blue bricks. So, what is a greenhouse made of?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

When 99 is considered higher than 100?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?