The postfix expression 2 4 6 * + 15 - 21 7 / + = evaluates to ____.
A) 4
B) 14
C) 24
D) 26

Question

Quizplus · Accepted Answer

Starting from the left, the postfix expression evaluates as follows:

1. Push 2 onto the stack: Stack: [2]
2. Push 4 onto the stack: Stack: [2, 4]
3. Push 6 onto the stack: Stack: [2, 4, 6]
4. Multiply 4 and 6 (the top two items on the stack): Stack: [2, 24]
5. Add 2 and 24 (the top two items on the stack): Stack: [26]
6. Subtract 15 from 26: Stack: [11]
7. Push 21 onto the stack: Stack: [11, 21]
8. Push 7 onto the stack: Stack: [11, 21, 7]
9. Divide 21 by 7 (the top two items on the stack): Stack: [11, 3]
10. Add 11 and 3 (the top two items on the stack): Stack: [14]

Therefore, the answer is 14.

The Postfix Expression 2 4 6 * + 15 -