Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

Can you count the number of triangles in the given figure?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

Why is the Hole below a Lock?

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?