GATE CSE 2015 | Set 3 | Question: 12

Question

The result evaluating the postfix expression $10  \ 5 + 60 \ 6 /  * 8 -$ is 

• A. $284$
• B. $213$
• C. $142$
• D. $71$

Comments

(((10+5)*(60/6))-8)

((15*10)-8)

150-8

142

 

Answer 1

We have to keep symbol into stack and when we get two operands followed by operator. We will apply operator on last two operands.$$\begin{array}{|ll|}\hline \textbf{symbol}  &  \textbf{stack } \\\hline \text{10} & \text{10 $\quad$ (keep in stack)}\\\hline \text{5} & \text{10 $\quad$ 5 $\quad$ (keep in stack)}\\\hline
\text{+} & \text{10 $\quad$ 5 $\quad$ + $\quad$ (apply operator on last 2 operands $\implies 10+5=15)$}\\\hline \text{60} & \text{15 $\quad$ 60 $\quad$ (keep in stack)}\\\hline  \text{6} & \text{15 $\quad$ 60 $\quad$ 6 $\quad$ (keep in stack)}\\\hline  
\text{/} & \text{15 $\quad$ 60 $\quad$ 6 $\quad$ / $\quad$ (apply operator on last 2 operands $\implies 60/6=10)$}\\\hline  
\text{*} & \text{15 $\quad$ 10 $\quad$ * $\quad$ (apply operator on last 2 operands $\implies  10*15=150)$}\\\hline   \text{8} & \text{150 $\quad$ 8 $\quad$ (keep in stack)}\\\hline   - & \text{150 $\quad$ 8 $\quad -\quad$ (apply operator on last 2 operands $\implies 50-8=142)$}\\\hline  \end{array}$$

So, answer is $142$.

Comments

This is just a woww explanation.

Read it once and you are just done,

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Yeah this solution is Insane Read once solve many. Fuking brutal solution this is

Answer 2

(10 + 5) * (60 / 6) - 8 = 15 * 10 - 8 = 142

Answer 3

10 5 + 60 6 / * 8 -

Operation	Symbol	Stack
	10 5 + 60 6 / * 8 -	NULL
Push	5 + 60 6 / * 8 -	10
Push	+ 60 6 / * 8 -	10 5
Pop	60 6 / * 8 -	(10 + 5)
Push	6 / * 8 -	(10 + 5) 60
Push	/ * 8 -	(10 + 5) 60 6
Pop	* 8 -	(10 + 5) (60/6)
Pop	8-	(10 + 5) * (60/6)
Push	-	[(10 + 5) * (60/6)]  8
Pop	Null	[(10 + 5) * (60/6)]  - 8

So after evaluation of    [(10 + 5) * (60/6)]  - 8 = 142 so option c is answer

Answer 4

This postfix expression can be evaluated using stack..

                                6

           5            60   60  10            8

    10  10    15  15   15  15   150   150     142

    10    5    +    60    6     /     *        8         -

Answer will be 142.

Answer 5

 

150-8 = 142

 

Answer 6

Colors speak more :p

Answer is 142 ie. (C)