Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

There are two beautiful yet remote islands in the South Pacific. The Islanders born on one island always tell the truth, and the Islanders from the other island always lie.
You are on one of the islands and meet three Islanders. You ask the first which island they are from in the most appropriate Polynesian tongue, and he indicates that the other two Islanders are from the same island. You ask the second Islander the same question, and he also indicates that the other two Islanders are from the same island.
Can you guess what the third Islander will answer to the same question?

Can you solve the below geography rebus by decoding the below rebus ?

Using mathematical symbols like +, -, and x in order to make the equations correct. Replace # with the above-given symbols.

9 # 8 # 7 # 6 # 5 # 4 = 91

On a certain day, John celebrated his birthday. Two days later, his older twin brother Jacob celebrated his birthday.

Is this even possible? How can it be?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

I know a nine-letter word having only one vowel.
Do you ?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?