By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

It's pretty hard to give up.
If you remove a part of it, you will be left with a bit.
Even if you remove another part, the bit still remains.
Remove one more and it still remains.

What is it?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

1 rabbit saw 9 elephants while going to the river. Every elephant saw 3 monkeys going toward the river. Each monkey had 1 parrot in each hand. How many animals are going towards the river?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

I have 50 feet long of cloth, I need to create 50 handkerchiefs each size of 1 foot. I take one minute to cut a 1-foot handkerchief. So how long will it take to cut 50 handkerchiefs?

If we tell you that there is a relation between the numbers and letters in the given figure, can you analyze it and find the missing letter in the last box?

How many triangles are there on the puzzle below?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99