We can handle the three conditions as filters instead of testing everything at once. We’ll first keep numbers divisible by six, use digit sums to remove those divisible by nine, and then verify that the remaining value has a nontrivial factor pair. Passing an early filter does not excuse failing a later one.
Inside Gozunta
Turn the preview into practice.
More than a preview
Gozunta lets you study this problem—and more than 10,000 others.
Create targeted learning sessions, use hints, check your answer, read the walkthrough, watch the video, print the work, and track your progress.
