Risa went to the gym once every 9 days while Kylie went to the same gym once every 2 days. They became friends after meeting each other at the gym on a Saturday. Which would be the next earliest day that they would meet each other again at the gym? Give the answer in number. (Eg Mon = 1; Tue = 2)
Multiples of 9: 0, 9, 18
Multiples of 2: 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24
Lowest common multiple of 9 and 2: 18
Number of weeks in 18 days
= 18 ÷ 7
= 2 r 4
By looking at the remainder, we count 2 weeks and 4 days from Saturday is a (3) Wednesday.
Answer(s): 3