Bheja Fry question

 This Bheja Fry question  I found on Internet.

It may look small and easy, but trust me it is not  !!!

Question 

If            5  +   3   =   28

                9  +  1  =  810

                8   +  6   =   214

Then       7  +  4   =  ???

Answer 

We know  5  +  3  =  8.  But here it is given that it is     28  !!!!

Before going to next line, we must come to know on what basis, 5 + 3  s 28

Since it is a brain teaser, we can apply all the mathematical function in whatever the way we want to get the answer  !!!!

We know  5  - 3  =  2

And        5  +  3   =   8

Putting these two results side  by  side, we get 

                5  +  3   = 28    !!!!

Now similarly,  7   +   4  =   311.