Solve below rebus puzzle?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

Why is Saturday stronger than Monday?

I can be cracked, made, told, and played. What am I?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Can you divide the below-given shape into four equal and identical pieces?

A mathematics teacher took exams for his students. Out of the total students, 25% passed both the tests included in the exam. However, only 42% were able to clear the first test.

Can you find out the percentage of those students who passed the first test and also passed the second test?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

If you drop a 15 kg iron bar and a 5 kg bag of cotton from a height of 50 meters which will reach the ground first?