How can you write nineteen in a manner that if we take out one, it becomes twenty?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

There are hundred red gems and hundred blue gems. The blue gems are priceless while the red gems equal wastage. You have two sacks one labeled Heads and the other Tails. You have to distribute the gems as you want in the two sacks. Then a coin will be flipped and you will be asked to pick up a gem randomly from the corresponding sacks.

How will you distribute the gems between the sacks so that the odds of picking a Blue gem are maximum?

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

Two trains start at the same time, one from Bangalore to Mysore and the other from Mysore to Bangalore. if they arrive at their destinations one hour and four hours respectively after passing one another, how much faster is one train running than the other?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?