Lee jogged in the gym once every 3 days. Flynn jogged in the same gym once every 5 days. They met on 6 November 2007. There are 30 days in November and 31 days in December.
- On which date they next met each other in the gym? Give your answer in the following format. (Eg 1 Jan 2000)
- How many times did they meet in the gym in November and December 2007?
(a)
Multiples of 3: 3, 6, 9, 12, 15
Multiples of 5: 5, 10, 15
LCM of 3 and 5: 15
Lee and Flynn met every 15 days.
15 days after 6 November 2007 = 21 Nov 2007
The day that they next met in the gym = 21 Nov 2007
(b)
Since Lee and Flynn first met on 6 November 2007, they did not meet for the first 5 days of November 2007.
Total number of days from 6 November 2007 to 30 December 2007
= 30 + 31 - 5
= 56
Number of sets of 15 days from 6 November to 30 December 2007
= 56 ÷ 15
= 3 r 11
On the first day of each of the 3 sets of 15 days, they would meet in the gym.
Since there is a remainder of 11, this means that on the first day of the remaining 11 days, they would meet in the gym again.
Number of times that they met in the gym in November 2007 and December 2007
= 3 + 1
= 4
Answer(s): (a) 21 Nov 2007; (b) 4
