Question

Ramon and Justine are watching different broadcasts of a parade on television. The broadcast Ramon is watching airs commercials every 17 minutes. The broadcast Justice is watching airs commercials every 14 minutes. Both broadcasts started at 7:00 a.m. and are scheduled to end at 9:00 a.m. When will commercials air on both broadcasts at the same time?
Explain your reasoning.

Answer 1

Since there is a short difference between the starting and ending times, we calculate the schedule of each commercial and then compare the broadcasting times.

Commercials of the broadcast Ramon is watching air at:

7.17,    7.34,     7. 51,    8.08,    8.25,    8. 42     8.59     a.m.

Commercials of the broadcast Justice is watching air at:

7.14        7.28        7.42       7. 56      8.10        8.24       8.38     8.52  a.m.

we can check that there are no matching commercial times.

The commercials will not air on both broadcasts at the same time in the interval 7:00 a.m to 9:00. a.m

Answer: never