What is the smallest number which is divisible by 15, 20, and 25?

The smallest number divisible by 15, 20, and 25 is 300. This is also known as the Least Common Multiple (LCM) of 15, 20, and 25.

To find the LCM, we can use prime factorization:

• 15 = 3 x 5
• 20 = 2 x 2 x 5 = 2² x 5
• 25 = 5 x 5 = 5²

To find the LCM, we take the highest power of each prime factor that appears in any of the numbers:

• 2² = 4
• 3¹ = 3
• 5² = 25

Then, we multiply these together:

LCM (15, 20, 25) = 2² x 3 x 5² = 4 x 3 x 25 = 300

Therefore, 300 is the smallest number that is divisible by 15, 20, and 25.