Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

If 21x = 79x, what is the value of x?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

Rearrange the letters in "new door" to make one word.

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

A man embarked on a questionnaire game. He kept asking the same question to whomever he found. The answer each time was different.

Can you guess what the question was?

John is selling fruits.
He sells grapes at $30, Dates $25, and a Wolfberry $45.
At what price does he sell fig?

PS: Logical Thinking

Mr Black, Mr Gray, and Mr White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr Black, who hits his shot 1/3 of the time, gets to shoot first. Mr Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr Black, where should you shoot first for the highest chance of survival?

If 1+9+8=1, what is 2+8+9?