What is the next number in this matchsticks series riddle?

A container contains 100 eggs. They can be either fresh or rotten. What is sure is the fact that there is at least one fresh egg in that container.

If you are asked to pick two eggs randomly from the container, at least one of them will be rotten.

Can you calculate how many eggs in that container are fresh?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

What does this rebus means ?

PROG WORKRESS

In a town, there are four houses located at different distances from each other. Following are the distances:

The third house is 60 meters apart from the first house.
The fourth house is 40 meters apart from the second house.
The third house is 10 meters nearer to the fourth house than it is to the second house.

Can you find out the distance between the fourth and the first house?

Can you solve this picture maths equation?

How can you make number one disappear by adding something to it?

You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

What goes up but never comes down?