Solution:

As the balloon lost altitude, all of the thieves took off their clothes in order to decrease the overall weight. but when balloon continues to lose the attitude they decide one of them need to jump to the desert to decrease the weight.
The man who must jump is decided by the famous death game where one who picks the shortest toothpick must die.
Frank Catton pick the half toothpick and was already naked and hence the hence explain his state in the desert.

Solution:

It can be done as shown in the picture below. Key to solving such problems is to fill the prime number first.

Solution:

3

Explanation:
Possible matches
Chelsea vs Tottenham
Chelsea vs ManCity
Chelsea vs Arsenal
Chelsea vs Liverpool
Tottenham vs ManCity
Tottenham vs Arsenal
Tottenham vs Liverpool
ManCity vs Arsenal
ManCity vs Liverpool
Arsenal vs Liverpool

Therefore there is a total of 10 matches. After every match, 2 points were distributed between two teams as:
Case1: One of team wins:
Winning team will get 2 points.

Case2: Match ends up in a draw
Both teams will share a point.

Therefore 10*2 = 20 points should be the sum of all team points.

6 + 5 + 4 + 2 + ? =20
? = 3

Solution:

Turn the equation to 180 degrees (upside down)

16 = 8 + 8.

Solution:

The node can be connected as shown.

Solution:

888

Explanation:
Part-1: Triangle
The triangle is an equilateral triangle.
The value of E and L is determined by the position in the English alphabets i.e E = 5 & L = 12. Together they form number 512

As we know that the equilateral triangle has 3 equal sides, therefore
X^3 = 512
X = 8
=> XXX = 888 ... (desired)

Part-1: X/3 = X
X is the 24th letter, therefore 24/3 = 8

Solution:

A

Explanation:
Pi = 3.141592653.....
All images are related by pi value i.e "The number of straight lines on each shape corresponds to the digits of pi."

Solution:

Terry was in the lift.

Solution:

They were facing each other and not back to back.

Solution:

Not sure.

John Brunner always sneezes before the rain, but it was not mentioned that if Brunner sneezes, it will rain.