What Deficiency does the below rebus represent?

VIT_MIN

A worker is to perform work for you for seven straight days. In return for his work, you will pay him 1/7th of a bar of gold per day. The worker requires a daily payment of 1/7th of the bar of gold. What and where are the fewest number of cuts to the bar of gold that will allow you to pay him 1/7th each day?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

The teacher told the student that if he told a lie then he will be expelled from school and if he told the truth then he still is expelled from school.

What can a student say to prevent his being expelled from school?

Why is the Hole below a Lock?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

Prove that the below maths equation is true.

8 + 8 = 91

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

How can you take 2 from 5 and leave 4?