Help me in solving 7 rings problem

My issue

Input Format
The first line of input will contain a single integer

T, denoting the number of test cases.
Each test case consists of two space-separated integers

N and

X — the number of items Chef bought and the cost per item.
Output Format
For each test case, output on a new line, YES, if the total bill is equivalent to a valid phone number and NO otherwise.

Each character of the output may be printed in either uppercase or lowercase. That is, the strings NO, no, nO, and No will be treated as equivalent.

Constraints
1

100
1≤T≤100
1

,

1000
1≤N,X≤1000
Sample 1:
Input
Output
4
25 785
402 11
100 100
333 333
YES
NO
YES
NO

My code

``````#include <stdio.h>
#include <string.h>
int main(void) {
int t;
scanf("%d",&t);
while(t--)
{
int N,X,mult;
scanf("%d %d",&N,&X);
mult=N*X;

scanf("%d",&mult);
if((strlen(mult)==5))
{
printf("yes\n");
}
else
{
printf("No\n");
}

}
return 0;
}

``````

Learning course: Basic Math using C
Problem Link: CodeChef: Practical coding for everyone

@modikishu88
plzz refer the following solution for better understanding of logic

``````#include <stdio.h>
#include<string.h>
int main(void) {
int t;
scanf("%d",&t);
while(t--)
{
int n,x;
scanf("%d %d",&n,&x);
int k;
k=n*x;
if(k>=10000 && k<=99999)
{
printf("YES\n");
}
else
{
printf("NO\n");
}

}
return 0;
}``````