Greatest common factor and least common multiple problem

Find a number, given its LCM and GCF with another integer

Determine how many stairs the staircase has, based on what happens when people leap up the stairs

Find how many multiples of two and three there are between two integers

Find how many integers are multiples of two and three, but not six.

Find the pattern. Study the list of numbers, and figure out what number is missing, and why

A problem involving dividing donuts evenly among a group of people

Factor the following number without use of your calculator