Question

4. On a holiday tree four strands of colored bulbs blink at different speeds. Strand A blinks
every 12 seconds, strand B every 15 seconus, strand C every 20 seconds and strand D every
25 seconds. If all four strands blink together at 1:30 P.M., the next time they will blink
together again is at _ P.M.​

Answer 1

Answer:

01:35 pm

Step-by-step explanation:

let's say after n min they will again blink together.

so if A blinked a times in n min then

12×a=n similarly

15×b=n

20×c=n and

25×d=n

as we are trying to find lowest value of n (question asks for when next they'll blink together), we are essentially looking for lowest common multiple of (12, 15, 20 & 25) which is 300. So after 5 minutes!!