Can you find out which number multiplied by itself will give the output as 12345678987654321?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

In a guessing game, five friends had to guess the exact numbers of apples in a covered basket.
Friends guessed 22, 24, 29, 33, and 38, but none of the guesses was correct. The guesses were off by 1, 8, 6, 3, and 8 (in random order).

Can you determine the number of apples in a basket from this information?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Using Only Five 5's and any mathematical operator make sum as 37

Can you decipher the following common phrase?

T M C
A U O
H S M
W T E

When 99 is considered higher than 100?

The more you take me, the more you leave me behind.
Who Am I?

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?

What word begins and ends with an E, but has only one letter?