What does this below rebus puzzle mean?

Decode below rebus
D
N
A
T
S , D

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

If a shopkeeper can only place the weights on one side of the common balance. For example, if he has weights 1 and 3 then he can measure 1, 3 and 4 only. Now the question is how many minimum weights and names of the weights you will need to measure all weights from 1 to 1000? This is a fairly simple problem and very easy to prove also.

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

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?

In a football game, Christina defeated Teresa by 2 - 0 but no man from either side scored. How can this be possible?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
----------

John is 45 years older than his son Jacob. If you find similarities between their ages, both of their ages contain prime numbers as the digits. Also, John's age is the reverse of Jacob's age.

Can you find their ages?