Question

a clock chimes every 20mins
a light flashes every 8 mins
the clock chimes and the light flashes together at 8:00

how many times between 8:01 and 12:30 will the clock chime and the light flash together?
show your working (5marks)

Answer 1

Answer: 6 times

Step-by-step explanation:

it is a lowest common multiple question. So we list the multiples

20                   8

40                   16

60                   24

80                   32

                      40

40 is our lowest common multiple. Which means every 40 minutes they flash and chime together.

so if we add 40 minutes onto 08:00 we get 08:40 and if we add it again we get 09:20 and again we get 10:00 and again we get 10:40 and again we get 11:20 and again we get 12:00. We have to stop here as if we add 40 minutes again we will go over the given time of 12:30. If we count how many times it was added. this adds to 6. therefore the answer is 6.  

hope this helped.

Answer 2

The clock will chime and the light flashes together 6 times.

How many times the clock will chime and light flash together?

The Least Common Multiple (LCM) of a group of numbers is the smallest number that is a multiple of all the numbers.It is the lowest common multiple question. So we list the multiple

20                   8

40                   16

60                   24

80                   32

                     40

40 is our lowest common multiple. This means every 40 minutes they flash and chime together.

so if we add 40 minutes onto 08:00 we get 08:40 and if we add it again we get 09:20 and again we get 10:00

and again we get 10:40 and again we get 11:20 and again we get 12:00. We have to stop here as if we add 40 minutes again we will go over the given time of 12:30.

If we count how many times it was added. this adds to 6. therefore the answer is 6.  

Therefore the clock will chime and the light flashes together 6 times.

To know more about LCM follow

https://brainly.com/question/233244

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