Calculate Largest Four digit Number which is divisible by 15

To find the largest 4-digit number exactly divisible by 15, we can use a straightforward method involving division and remainders.

Step-by-Step Calculation

1. Identify the largest 4-digit number: The largest 4-digit number is 9999.

2. Divide by the divisor (15): Divide 9999 by 15 to find the remainder.

   • 9999 / 15 = 666 with a remainder of 9.

3. Subtract the remainder: To find the largest number less than or equal to 9999 that is perfectly divisible by 15, subtract the remainder (9) from 9999.

   • 9999 - 9 = 9990.

Alternatively, you can verify this using the divisibility rules for 15, which requires a number to be divisible by both 3 and 5:

• Rule for 5: The number must end in 0 or 5. 9990 ends in 0, so it is divisible by 5.

• Rule for 3: The sum of the digits must be divisible by 3. 9 + 9 + 9 + 0 = 27, which is divisible by 3.