## abdul_shabeer 3 years ago A clock gains 2 minutes per day and another loses 3 minutes per day. Both the clocks are started on a correct time at a given instant. They will again show the correct time for an instant within

1. abdul_shabeer

(a) a week (b) a month (c) six months (d) one year

2. GT

I tried this before but could not formulate the equation. hmmmm....

3. 14yamaka

wait, is this a digital clock? like is it 12 hours or 24 hours we're going for?

4. abdul_shabeer

I think 12 hours clock

5. 14yamaka

one of the easier ways would be is to multiply to figure out the total number of minutes there are in the 12 hours and divide it by 5.

6. 14yamaka

Each day, the clocks have gain a 5-minute gap between each other, so how big does the gap have to be to become 12 hours :)

7. fewscrewsmissing

I would say... 720 minutes per 12 hours, so the 2 minutes clock will be accurate again in 720/2/2 days = 180 days, the -3 minutes clock in 720/3/2 = 120 days. LCM of 180 and 120 is 360, so once a year?

8. fewscrewsmissing

But it's late here so my ability to reason left hours ago =)

9. FoolForMath

Yes once a year is the correct answer.

10. GT

I think that is right......

11. abdul_shabeer

Yes, it matches the answer key

12. GT

Good way to set it up.

13. 14yamaka

oooohhh ok:) its 1:25 in the morning here :S lol

14. fewscrewsmissing

Haha where are you 14yamaka? It's 12:25am here.

15. 14yamaka

japan haha

16. FoolForMath

As we are giving away our local time it's 9:55 PM here.

17. 14yamaka

Where are you FSM?

18. 14yamaka

and where are you Fool?

19. abdul_shabeer

I think FFM is in India

20. FoolForMath

I am from India and FSM is from Australia.

21. fewscrewsmissing

Ah tis but early for you FFM :-P I'm in Perth, Australia.

22. amir.sat

after 3600 days

23. fewscrewsmissing

3600 days = 10 years o.O

24. 14yamaka

whoa, that's 10 years

25. abdul_shabeer

Why the 2 minutes clock will be accurate again in 720/2/2 days?

26. amir.sat

2 minute clock after 1800 days 3 minute clock after 1200 days

27. abdul_shabeer

Is it 1800 or 180?

28. amir.sat

1800

29. fewscrewsmissing

I've shown my reasoning above, I got 180 days. I don't know HOW it could be 1800 or 1200 days, can you elaborate amir.sat?

30. fewscrewsmissing

So...?