What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

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

A King wants to send the diamond ring to his girlfriend securely. He got multiple locks and their corresponding keys. His girlfriend does not have any keys to these locks and if he sends the key without a lock, the key can be copied in the way. How can King send the ring to his girlfriend securely?

Find the missing number in the sequence below:

What is the riddle which can be asked all day with a different correct answer each time.

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

What does this rebus mean?

O
N
C
E
TIME

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.

Today is John's birthday.
A year ago, John had five candles and he lit all the candles except the one at the last.
Now he is going to light all the candles.

How old is John Today?

(He is not five today.....)

Why is it very easy to weigh a fish?