Question

the trafik lights at 2 diferent cross roads change for eevery 40 seconds and 32 seconds. at one time change together at what interval they change together
pls give me by explaining
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Answer 1

Step-by-step explanation:

The traffic light at three different road crossing change after every 48 seconds,72 seconds and 108 seconds, respectively.

So let us take the LCM of the given time that is 48 seconds, 72 seconds, 108 seconds

⇒ 48 = 2 × 2 × 2 × 2 × 3

⇒ 72 = 2 × 2 × 2 × 3 × 3

⇒ 108 = 2 × 2 × 3 × 3 × 3

Hence, LCM of 48, 72 and 108 = (2 × 2 × 2 × 2 × 3 × 3 × 3)

LCM of 48, 72 and 108 = 432

So after 432 seconds, they will change simultaneously

We know that

60 seconds = 1 minute

so on dividing 432 / 60, we get 7 as quotient and 12 as a reminder

Hence, 432 seconds = 7 min 12 seconds

∴ The time = 7 a.m. + 7 minutes 12 seconds

Hence, the lights change simultaneously at 7:07:12 a.m

Answer 2

Step-by-step explanation:

Changing time of 1st traffic light:- 40 seconds

Changing time of 2nd traffic light:- 32 seconds

So,we have to find LCM of 40 and 32 it is 160.

So, after every 160 seconds means after every 2 minutes and 40 seconds they change together.