Question 28: How many three-digit numbers are common multiples of a and b, given that BCNN(a,b)=300

BCNN(a,b) = 300

BC(a,b) is a multiple of 300.

⇒ All 3-digit numbers that are common multiples of a and b are: 300, 600, 900

So there are a total of 3 three-digit numbers that are multiples of a and b.