The largest number of four digits that is divisible by 12, 15 and 18 is ________.
- A9450
- B9900
- C9000
- D9750
Solution & Step-by-step Explanation
To find the largest 4-digit number divisible by 12, 15, and 18, we first need to find the Least Common Multiple (LCM) of these numbers.
Step 1: Find the LCM of 12, 15, and 18
Prime factorization of 12=2
2
×3
Prime factorization of 15=3×5
Prime factorization of 18=2×3
2
LCM(12,15,18)=2
2
×3
2
×5=4×9×5=180
Step 2: Divide the largest 4-digit number by the LCM
The largest 4-digit number is 9999.
180
9999
=55 with a remainder of 99
Step 3: Subtract the remainder from 9999
Required Number=9999−99=9900
Therefore, 9900 is the largest 4-digit number divisible by 12, 15, and 18.
Step 1: Find the LCM of 12, 15, and 18
Prime factorization of 12=2
2
×3
Prime factorization of 15=3×5
Prime factorization of 18=2×3
2
LCM(12,15,18)=2
2
×3
2
×5=4×9×5=180
Step 2: Divide the largest 4-digit number by the LCM
The largest 4-digit number is 9999.
180
9999
=55 with a remainder of 99
Step 3: Subtract the remainder from 9999
Required Number=9999−99=9900
Therefore, 9900 is the largest 4-digit number divisible by 12, 15, and 18.