Determine if 25110 is divisible by 45. [Hint : 5 and 9 are co-prime numbers. Test the divisibility of the number by 5 and 9.]

We have

45 = 3 × 3 × 5

So, 45 = 5 × 9

Let’s check if 25110 is divisible by 5

Since 25110 has 0 as its unit digit, therefore, 25110 is divisible by 5

Let’s find the sum of the digits

2+5+1+1+0 = 9

Since 9 is divisible by 9

Therefore, 25110 is also divisible by 9

Since 25110 is divisible by both 5 and, it is divisible by 45

Thus, 25110 is divisible by 45