Six bells start tolling at the same time and at 2, 4, 6, 8, 10, and 12 second intervals, respectively. How many times do they toll jointly in 30 minutes?
A. 4
B. 10
C. 15
D. 16
Answer:D
Six bells start tolling at the same time and at 2, 4, 6, 8, 10, and 12 second intervals, respectively. How many times do they toll jointly in 30 minutes?
A. 4 B. 10 C. 15 D. 16
Explanation: The L.C.M. of two, four, six, eight, ten, and twelve equals 120.As a result, every 120 seconds, the bells will chime together (2 minutes).They will toll together 30/2+ 1 = 16 times in 30 minutes.