Mathematics for IGCSE & O level - Number (Section 3 - No. 8)
Buses to Shenley leave every 40 minutes and buses to Winley leave every 15 minutes. If buses to both places leave at 8.15 a.m., when is the next time they leave at the same time?
8.30 a.m.
9.15 a.m.
9.00 a.m.
9.45 a.m.
Explication
Find the LCM of 40 and 15, which is 120 minutes, or 2 hours. Therefore, the buses will leave together again at 10:15 a.m.