What does this rebus mean?

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I have two coins.
* One of the coins is a faulty coin having a tail on both sides of it.
* The other coin is a perfect coin (heads on side and tail on other).

I blindfold myself and pick a coin and put the coin on the table. The face of the coin towards the sky is the tail.

What is the probability that another side is also tail?

Who can jump higher than a Mountain?

Find the missing number in the sequence below:

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?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

What kind of band never plays music?

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?

What has 88 keys?

The sum of a mother, her baby and her dog's weight is 170 Kg. How much does the baby weigh if the mother weighs 100 kg more than the combined weight of the baby and the dog, and the dog weighs 60 per cent less than the baby?