Arithmetic operators in C++ - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of mixed arithmetic operations

What is the output of the following C++ code?

C++

#include <iostream>
int main() {
    int a = 5, b = 3, c = 2;
    int result = a + b * c - b / c;
    std::cout << result << std::endl;
    return 0;
}

A 9

B 10

C 11

D 8

💡 Hint

Remember the order of operations: multiplication and division before addition and subtraction.

Multiplication and division (left-to-right) happen before addition and subtraction. So b * c = 3 * 2 = 6, b / c = 3 / 2 = 1 (integer division). Then a + 6 - 1 = 5 + 6 - 1 = 10.

❓ Predict Output

intermediate

Result of integer division and modulo

What is the output of this C++ code snippet?

C++

#include <iostream>
int main() {
    int x = 17, y = 5;
    std::cout << x / y << " " << x % y << std::endl;
    return 0;
}

A 3 3

B 2 3

C 2 2

D 3 2

💡 Hint

Integer division discards the decimal part. Modulo gives the remainder.

17 divided by 5 is 3 with remainder 2. So output is '3 2'.

❓ Predict Output

advanced

Output of mixed signed and unsigned arithmetic

What is the output of this C++ code?

C++

#include <iostream>
int main() {
    int a = -3;
    unsigned int b = 2;
    std::cout << a + b << std::endl;
    return 0;
}

A 4294967295

B -1

C 0

D 1

💡 Hint

When mixing signed and unsigned, signed is converted to unsigned.

The signed int -3 is converted to unsigned int, which becomes a large number (on 32-bit unsigned, 4294967293). Adding 2 gives 4294967295.

❓ Predict Output

advanced

Result of floating point division and multiplication

What is the output of this C++ program?

C++

#include <iostream>
int main() {
    double x = 7.5, y = 2.5;
    double result = x / y * y;
    std::cout << result << std::endl;
    return 0;
}

A 7.5

B 7.499999999999999

C 10

D 2.5

💡 Hint

Floating point arithmetic can have small precision errors, but this calculation should return the original value.

7.5 / 2.5 = 3.0, then 3.0 * 2.5 = 7.5 exactly, so output is 7.5.

🧠 Conceptual

expert

Understanding operator precedence and associativity

Given the expression in C++:
int x = 4 + 3 * 2 / 6 - 1;
Which of the following shows the correct order of operations applied?

A Multiply, Add, Divide, Subtract

B Add, Multiply, Divide, Subtract

C Multiply, Divide, Add, Subtract

D Divide, Multiply, Add, Subtract

💡 Hint

Multiplication and division have the same precedence and are evaluated left to right before addition and subtraction.

Multiplication and division are done first, from left to right, then addition and subtraction. So multiply (3*2=6), divide (6/6=1), then add (4+1=5), then subtract (5-1=4).