At a party, every eighth guest gets a pen and every ninth guest gets a mug. What is the position of the first guest that will get both a pen and a mug?
Multiples of 8: 8, 16, 24, 32, 40, 48, 56, 64, 72
Multiples of 9: 9, 18, 27, 36, 45, 54, 63, 72
Position of first guest that gets both a pen and mug
= Lowest common multiple of 8 and 9
= 72
Answer(s): 72
