What does this simple rebus mean?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

81 x 9 = 801. What must you do to make the this equation true?

Can you spot the man between the coffee bean in the picture below ?

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?

Can you solve below mathematical equation?

2^1234 - 2^1233

The owner of a popular clothing store comes up with his own method of pricing items. A vest costs $8, socks cost $10, a tie costs $6, and a blouse costs $12. Using the owner’s method, how much would a pair of underwear cost?

Why do you find that most of the buildings are deprived of the 13th floor?