Question

Three bulbs flash at regular intervals of 30, 36 and 45 seconds respectively. They flash together at same time in the morning. After how many seconds will they flash together?.
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Answer 1

Answer:

162 sec

Step-by-step explanation:

LCM OF 30, 36, AND 45

30 = 2 * 3 * 5

36 = 2 * 2 * 3 * 3

45 = 3 * 3 * 5

LCM = 2^2 * 3^2 * 3^2 * 2^1 * 3^1 * 5^1

LCM = 4 * 9 * 9 * 2 * 3 * 5

9720/60 = 162