# Write a program to find the greatest number among the three numbers

By | October 4, 2021 ## Problem Statement

We have given 3 numbers `num_1` , `num_2` and `num_3`, as input from the user and we need to write a script or program that print the greatest one.

For Example

Input

```num_1 = 20
num_2 = 30
num_3 = 40```

Output

`The greatest number is: 40`

## Solution

The problem is very simple and beginner level. To solve the problem we just need to check if the `num_1` is greater or equal to than `num_2` and `num_3`. If yes we will print the `num_1`is the greatest, if not we will check if `num_2` is greater than or equal`num_1` and num_3 if yes we will print that `num_2` is the greatest. Even if `num_2` is not the greatest we will simply print that num_3 is the greatest.

To solve this problem we only require of…else statement.

### C program to find the greatest number among the three numbers

```#include <stdio.h>

int main()
{
int num_1,num_2,num_3;
//input the first number
printf("Enter the first number: ");
scanf("%d", &num_1);

//input the second number
printf("Enter the second number: ");
scanf("%d", &num_2);

// input the third number
printf("Enter the third number: ");
scanf("%d",&num_3);

//if the number 1 is the greatest
if(num_1 >= num_2 && num_1>=num_3)
printf("The greatest number is: %d",num_1);

// if teh number 2 is the greatest
else if(num_2 >=num_1 && num_2>=num_3)
printf("The greatest number is: %d",num_2);

// if the number 3 is the greatest
else
printf("The greatest number is: %d" ,num_3);
return 0;
}```

Output

```Enter the first number: 12
Enter the second number: 45
Enter the third number: 15
The greatest number is: 45```

### C++ program to find the greatest number among the three numbers

```#include<iostream>
using namespace std;
int main()
{
int num_1,num_2,num_3;

//input the first number
cout<<"Enter the first number: "; cin>>num_1;

//input the second number
cout<<"Enter the second number: "; cin>>num_2;

//input the third number
cout<<"Enter the third number: "; cin>>num_3;

//check if number 1 is the greatest
if(num_1 >= num_2 && num_1>=num_3)
cout<<"The greatest number is: "<<num_1;

//check if number 2 is the greatest
else if(num_2 >=num_1 && num_2>=num_3)
cout<<"The greatest number is: "<<num_2;

//if the number 3 is the greatest
else
cout<<"The greatest number is: " <<num_3;
return 0;
}```

Output:

```Enter the first number: 12
Enter the second number: 23
Enter the third number: 54
The greatest number is: 54```

### Python program to find the greatest number among the three numbers

```# input the first number
num_1= int(input("Enter the first number: "))

# input the second number
num_2= int(input("Enter the second number: "))

# input the third number
num_3= int(input("Enter the third number: "))

# if the number 1 is the greatest
if num_1>=num_2  and num_1 >= num_3:
print("The greatest number is:", num_1)

# if the numer 2 is the greatest
elif num_2>=num_1  and num_2 >= num_2:
print("The greatest number is:", num_2)

# if the number 3 is the greatest
else:
print("The greatest number is:", num_3)
```

Output:

```Enter the first number: 45
Enter the second number: 78
Enter the third number: 23
The greatest number is: 78```

### Wrapping Up!

In this programming tutorial, we learned how to find out the greatest number among 3 numbers. The trick to solve this problem is lies behind the use of `if....else` statements with proper conditions. Here we only have 3 numbers which mean we can easily use the `if....else` statement and check for every number if the number is greater than or equal to the other two numbers.