GATE CS 2025 Set 2 Q.63: Functions, Recursion, Scope and Storage Classes

Consider the following C program:

#include <stdio.h>

int g(int n) {
    return (n+10);
}

int f(int n) {
    return g(n*2);
}

int main() {
    int sum, n;
    sum=0;
    for (n=1; n<3; n++)
        sum += g(f(n));
    printf ("%d", sum);
    return 0;
}

The output of the given C program is ________. (Answer in integer)

Your answer

Official answer and solution

Official answer: 46
From: Official GATE 2025 answer key

Solution

Express g(f(n)) algebraically as $2n + 20$ and sum over $n = 1, 2$ .

From the function definitions:

$g(n) = n + 10$
$f(n) = g(2n) = 2n + 10$
$g(f(n)) = (2n + 10) + 10 = 2n + 20$

The for loop executes for $n = 1$ and $n = 2$ :

For $n = 1$ : $g(f(1)) = 2(1) + 20 = 22$
For $n = 2$ : $g(f(2)) = 2(2) + 20 = 24$

Thus sum $= 22 + 24 = 46$ .

Final answer

The answer is the one in the official GATE answer key. The solution is this site's own explanation.

Source

Paper: GATE 2025 Computer Science and Information Technology - Session 2 (CS2)
Question: 63 of 65
Section: Computer Science and Information Technology

Report an error in this question

GATE questions are the work of the organising institutes. This site is independent and is not affiliated with them.

Question

Solution

Source