Solution:

In Mansion M2, we know that older child is boy, therefore there are two cases
Older Younger
Boy Girl
Boy Boy
Probability of at least one girl child: 1/2 => 50%

In Mansion M1 there are three cases
Older Younger
Boy Girl
Boy Boy
Girl Boy
Probability of at least one girl child: 2/3 => 66.67%

Solution:

Wednesday

Explanation :
There is two way to interpret this.
A) If x + 1 ==> x - 1
Then
x ==> x - 2
x - 2 = Friday
x = Sunday

B)If x - 1 ==> x + 1
Then
x ==> x + 2
x + 2 = Friday
x = Wednesday

Option B) makes sense and hence the answer.

Solution:

Felix

Explanation:
Iron = Fe (chemical symbol)
59 = LIX (Roman numerals)

Solution:

The missing wheel was the Stepney and hence Willian easily escapes just by driving.

Solution:

It can be done as shown below in the picture.

Solution:

Adam betrayed Eve.

Explanation:
Eve may not jump because of the survival instinct or can be related to some emotions and can, therefore, be given a benefit of the doubt, whereas Adam having the parachute seem a calculated plan implies that he definitely betrayed Eve.

Solution:

Federer serves first

Explanation:
The one who serves first can serve 5 and other will serve four.

== Option A ==
If Federer serve 4 and Nadal serve 5
Then five service breaks and Federer winning 6:3 not possible.

== Option B ==
Federer serve 5 and Nadal serve 4
There are five service breaks and score is Federer 6 - Nadal 3
i.e
On Federer serve, Federer wins 3 and lost 2
On Nadal serve, Federer wins 3 and lost 1

Solution:

No

Explanation:
Assume that the rope can be stretched forever. Assume the rope is evenly stretched. The moving speed of the end point of the rope (relative to the starting point) is 1000 cm/second.

Each second the ant moves 1cm, at the same time that 1cm rope stretches to be 1000+1000t1000+1000(t−1)= t+1tcm where t is the number of seconds after the ant is on the rope. Therefore, the ant has a moving speed of t+1t cm/second.

Therefore, the moving speed of the ant is far less than the moving speed of the end point of the rope.

Filk will never reach the end of the 1000 cm long rope.

Solution:

Terry was born in the Southern Hemisphere.

Solution:

In a clock.

Explanation:
time is 12 hour 10 minutes (here by looking at 2, we say 10 minutes)