What is the highest common factor of 375?

Answer 1

1). "Common" means "same for both". There's nothing common

until you have at least two separate numbers.

2). If you want the highest, then there can only be one of them.

Two different factors can't both be the highest.

Answer 2

You need at least two numbers to find something in common.

Answer 3

You need at least two numbers to find a GCF. If that's 3 and 75, the GCF is 3.