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

What does it mean?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

Can you find the least possible number such that

If the number is divided by 3, it gives the remainder of 1;
If the number is divided by 4, it gives the remainder of 2;
If the number is divided by 5, it gives the remainder of 3;
If the number is divided by 6, it gives the remainder of 4.

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

A Club organizes a Running Race, and John, Jacob, Minda, and Tony participated.

The results are as follows

John beats Jacob
Minda beats Toni
Toni beats John

Who came first in the race?

There are 3 apples in the basket and you take away 2. How many apples do you have now?

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?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?