What does the below rebus riddle means?

Baseball bat and ball cost $100. If the bat cost $99 more than the ball, what is the cost of each?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

In a supermarket, there is an intelligent glass pane before a refrigerating unit. This glass pane allows cherries and apples through it but does not allow grapes and Orange to pass through it.

Can you identify the rule that the glass pane is following?

In the Wild West, you are challenged into a death match by two bounty hunters nicknamed Golden Revolver (GR) and Killer Boots (KB). You accept the challenge. None of you want to waste any of the bullet and so a certain rules are laid down:

1) All of you will shoot in a given order till the last man standing.
2) Each of you shoots only once upon his turn.
3) If any one of you is injured, the other two will finish him off with an iron rod.
4) The worst shooter of all (which is you) shoots first and the best one shoots at the last.

Now, how will you plan things if you know that you hit every third shot of yours, KB hits every second shot and GR hits every shot ?

What is the next number?

77, 49, 36, 18 ?

A clock loses 10 minutes each hour. If the clock is set correctly at noon, what time is it when it reads 3 PM?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not-rounded numerals equals 24.