Question

Q3) He decorated the path in his garden with LED bulbs in three rows so that the bulbs in the first row blink at every 4 min, the bulbs in the second row blink at every 6 min and the bulbs in the third row blink at every 8 min. When will they blink together for the first time if he switches the lights on together at 6pm?

6.24 pm
6.30 pm
6.40 pm
They will not blink together at any time

Q4) If so, which is the next time they blink together?

 6.28 pm
6.48 pm
6.50 pm
None of these. ​

Answer 1

They will blink together at 24minutes

Explanation:

Using product of primes

4 = 2²

6 = 2 × 3

8 = 2³

Prime numbers with highest power

2³ × 3

8 x 3

24 minutes.