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

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

I have two sand hourglasses:
1. A 7 minute one and
2. An 11-minute one.

Using just these 2 sand hourglasses, how can I measure time as 15 minutes?

There is an ancient kingdom where every married woman keeps information regarding the fidelity of other men. However, what they don't know is the fidelity of their own husbands. Also, there is an ancient belief that they don't tell each other about the fidelity of their husbands.

On a certain day, the queen of the kingdom declares that she has identified at least one unfaithful man in the kingdom. She allows the wives to identify and gives them authority to kill their husbands if they are unfaithful at midnight.

How will the wives manage it?

Which number comes next in the number series?

2, 9, 30, 93, ?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

You are playing as white and given four rooks to checkmate the black king in four moves with the following rules 1. You can place one rook every move and ensure the black king should be in check position.2. After four moves the black king should be in the checkmate position.

Can you find a seven digit number which describes itself. The first digit is the number of zeros in the number. The second digit is the number of ones in the number, etc. For example, in the number 21200, there are 2 zeros, 1 one, 2 twos, 0 threes and 0 fours.

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

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211