Question

the traffic lights at four different crossings change at intervals of 48 second 72 second 90 second and 108 seconds respectively 20 life change together at 7:05 p.m. when will they change together again​

Answer 1

Hi dear here’s your answer

Answer:

Given

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

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Answer 2

Explanation:

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

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

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

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

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

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

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 × 3Hence, LCM of 48, 72 and 108 = (2 × 2 × 2 × 2 × 3 × 3 × 3)LCM of 48, 72 and 108 = 432

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 × 3Hence, LCM of 48, 72 and 108 = (2 × 2 × 2 × 2 × 3 × 3 × 3)LCM of 48, 72 and 108 = 432So after 432 seconds, they will change simultaneously

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 × 3Hence, LCM of 48, 72 and 108 = (2 × 2 × 2 × 2 × 3 × 3 × 3)LCM of 48, 72 and 108 = 432So after 432 seconds, they will change simultaneouslyWe know that

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 × 3Hence, LCM of 48, 72 and 108 = (2 × 2 × 2 × 2 × 3 × 3 × 3)LCM of 48, 72 and 108 = 432So after 432 seconds, they will change simultaneouslyWe know that60 seconds = 1 minute

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 × 3Hence, LCM of 48, 72 and 108 = (2 × 2 × 2 × 2 × 3 × 3 × 3)LCM of 48, 72 and 108 = 432So after 432 seconds, they will change simultaneouslyWe know that60 seconds = 1 minuteso on dividing 432 / 60, we get 7 as quotient and 12 as a reminder

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 × 3Hence, LCM of 48, 72 and 108 = (2 × 2 × 2 × 2 × 3 × 3 × 3)LCM of 48, 72 and 108 = 432So after 432 seconds, they will change simultaneouslyWe know that60 seconds = 1 minuteso on dividing 432 / 60, we get 7 as quotient and 12 as a reminderHence, 432 seconds = 7 min 12 seconds

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 × 3Hence, LCM of 48, 72 and 108 = (2 × 2 × 2 × 2 × 3 × 3 × 3)LCM of 48, 72 and 108 = 432So after 432 seconds, they will change simultaneouslyWe know that60 seconds = 1 minuteso on dividing 432 / 60, we get 7 as quotient and 12 as a reminderHence, 432 seconds = 7 min 12 seconds∴ The time = 7 a.m. + 7 minutes 12 seconds