MULTIPLES 2:
In the opening hour of a new store, a bell rang every 2 minutes and lights flashed every 3 minutes. If the store opened at 10 o'clock, at what times did both events happen at the same time? EXPLAIN or sketch and attach a diagram to show the strategy you used.
ReplyDeleteIf the doorbell rang every 2 minutes and the light flashes every 3 minutes then they go at the same time every six minutes; here are my calculations:
2 + 2 = 4 + 2, 6+2, 8+2, 10+2, 12+2, 14+2, 16+2, 18+2, 20+2, 22+2, 24+2, 26+2, 28+2, 30+2, 32+2, 34+2, 36+2, 38+2, 40+2, 42+2, 44+2, 46+2, 48+2, 50+2, 52+2, 54+2, 56+2, 58+2, 60
3 + 3 = 6+3, 9+3, 12+3, 15+3, 18+3, 21+3, 24+3, 27+3, 30+3, 33+3, 36+3, 39+3, 42+3, 45+3, 48+3, 51+3, 54+3, 57+3, 60
Clock time when activates happen at the same time:
10:06 10:12 10:18 10: 10:30 10:36 10:48 10:54 10:60
bell rang every 2 minutes
ReplyDeletelights flash every 3 minutes
10:00 AM
First you need to find the factors in LCM
2 = 2,4,6,8,19,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50,52,54,56,58,60
3 = 3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60
I went to 60 because there are 60 minutes in an hour.
LCM = 6
So every 6 minutes the bell rings and the light flashes at the same time.
10:06, 10:12, 10:18; 10:24; 10:30; 10:36; 10:42; 10:48, 10:54, 11:00 etc