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

How many letters are in the alphabet?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?

If six children and two dogs were under an umbrella, how come none of them got wet?

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

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

Find the smallest sentence with all the English alphabet.

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

I can write cow in 13 letters.

Can You?