**CBSE NET JUNE 2014 PAPER III**

The reverse polish notation equivalent to the infix expression

((A + B) * C + D) / (E + F + G) is

**(A)** A B + C * D + E F + G + / **(B)** A B + C D * + E F + G + / **(C)** A B + C * D + E F G + +/ **(D)** A B + C * D + E + F G + /

**Ans:-A**

**Explanation:-**

Always the expression given within parenthesis is converted first. Since there are 2 expressions with the parenthesis, I am going with the expression (E + F + G) first, the order does not matter.

In the expression (E + F + G), there are 3 operands E,F and G and two operators, both being +. Since both the operators are the same, the expression is going to be evaluated from left to right. So E + F is considered first and converted into postfix form which is EF+. So, the expression becomes,

( ( A + B ) * C + D) / (**[E F +]** + G)

Any expression converted into postfix form is going to be written in square brackets.

( ( A + B ) * C + D) / **[ E F + G + ]**

. Here EF+ is one operand, G is another operand and + is the operator.

The next expression to be converted into postfix is ( A + B).

( **[ A B + ]** * C + D) / **[ E F + G + ]**

Now, the expression which is enclosed in parenthesis is evaluated and so, we get

( **[ [ A B + ] C * ]** + D) / **[ E F + G + ]**

**[ A B + C * D + ] **/ **[ E F + G + ]**

**[ A B + C * D + ] ****[ E F + G + ] / **

Answer is, final postfix expression A B + C * D + E F + G + /.