What work can one never finish?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

Before Mount Everest was discovered, what was the highest mountain in the world?

Can you find out the missing number in the grid?

How can you tell a raw egg from a hard-boiled egg?

Can you identify the hidden rebus in the image below?

Why did Buffon take the goal with him after every Juventus match?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

In the Mexico City area, there are two Houses H1 and H2. Both H1 and H2 have two children each.
In House H1, The boy plays for Mexico Youth academy and the other child plays baseball.
In House H2, The boy Plays soccer for his school in Mexico and they recently have a newborn.

Can you prove that the probability of House-H1 having a girl child is more than that of House-H2?

What has one letter and starts with an E?