8:54 a. m.

9:12 a. m.

9:24 a. m.

10:24 a. m.

11:18 a. m.

Light A flashes every 12 minutes, and light B

flashes every 18 minutes. The two lights flash

at the same time at 8:00 a. m. At how many of

the times listed above will they again both

flash at the same time?

F. 1

G. 2

H. 3

J. 4

K. 5

Question

Mathematics

Amos

27 September, 02:57

8:54 a. m.

9:12 a. m.

9:24 a. m.

10:24 a. m.

11:18 a. m.

Light A flashes every 12 minutes, and light B

flashes every 18 minutes. The two lights flash

at the same time at 8:00 a. m. At how many of

the times listed above will they again both

flash at the same time?

F. 1

G. 2

H. 3

J. 4

K. 5

+3

Answers (1)

Know the Answer?

Matthias Schmidt · Answer 1

Hello,

The two lights flash at the same time every 18 min

at 8:00 h=480 min = 480+0*36

at 8:36 h=516 min = 480+1*36

...

54 is not divisible by 36

60+12=72 = 2*36 yes

60+24=84 not

120+24=4*36 yes

180+18=198 not

So 2 times are correct 9:12 and 10:24

Answer G

8:54 a. m.9:12 a. m.9:24 a. m.10:24 a. m.11:18 a. m.Light A flashes every 12 minutes, and light Bflashes every 18 minutes. The two lights flashat the same time at 8:00 a. m. At how many ofthe times listed above will they again bothflash at the same time?F. 1G. 2H. 3J. 4K. 5