Solution:

The ten difference are as follows:
1) The direction of the paper plane is changed.
2) The amount of white flowers is different.
3) There is one extra bird.
4) The shoes of the girl are plain white.
5) One snail is missing from the picture.
6) There is one extra butterfly.
7) One apple is missing from the picture.
8) Different number of dots of the bow of the girl.
9) There is one extra plant.
10) If you notice, an airplane is missing from the ground.

Solution:

2 degree below zero

Solution:

I filled a glass full of water and held it over my head for 20 minutes.

Solution:

Birbal drew another line that was larger than the pre-drawn line. Now the pre drawn line was smaller.

Solution:

31

Explanation:
Ramanujan lighting the candles in binary.
11110 =30
11111 =31

Solution:

They used the planks in the manner that is shown in the figure.

Solution:

73

Explanation:
It's a very famous puzzle known as "Josephus Problem Puzzle". It can be solved in various ways but the trick to solve this problem is illustrated below.

Binay number of 100 is: 1100100
complement pf 100 is 0011011, whose decimal equivalent is 27.
The desired answer will be 100 - 27 = 73

Solution:

This statement is true but only in a specific case i.e. if both of the siblings continue to live till the day the younger is as old as the elder one was during the time of their birth.

Solution:

Costa

Explanation:
c + 1 characters-> d
o + 2 characters-> q
s + 3 characters-> v
t + 4 characters-> x
a + 5 characters-> f

=> dqvxf = costa

Solution:

The probability of two numbers being relatively prime is 60%. Thus if you keep playing the bet, you will hypothetically make 20 cents on every play.

Thus, you should accept the bet.

Solution:

457730 * 4 = 1830920
(DOLLAR * 4 = QUARTER)