Question

How many numbers less than 100 are the product of 3 distinct primes?

Answer 1

Starting with the product of the first 2 primes, I'd divide that into 100 to find the maximum 3rd prime value:

100/6 = 16 2/3

So the 3rd prime would have to be less than 16 2/3

So the products of 6 with the remaining primes are:
30, 42, 66, 78

The next smallest product pair would be 10, and the remaining prime products would be:
70

So I'd say "5 numbers less than 100 are the product of 3 distinct primes".

Final answer. :-)