If two incorrect watches are set at 12:00 noon at correct time, when will both watches show the correct time for the first time given that the first watch gains 1 min in one hour and second watch looses 4 min in two hours.
A. 6 PM, 25 days later
B. 12 noon, 30 days later
C. 12 noon, 15 days later
D. 6 AM, 45 days later
E. None of these
Answer: Option B
Solution (By Examveda Team)
First watch: It shows correct time when it creates difference of 12 hours. So, to create difference of 12 hour, time required = $$\frac{{60 \times 12}}{{24}}$$ = 30 daysSecond watch: It shows correct time when it creates difference of 12 hours. So, to create difference of 12 hour, time required = $$\frac{{30 \times 12}}{{24}}$$ = 15 days Now, LCM of 30 and 15 gives the time when they show correct time together. Thus, required time = 30 days, at same time.
This Question Belongs to Arithmetic Ability >> Speed Time And Distance
How it is known that watches will show correct time when they create a difference of 12 hrs
It's a Wrong Answer. The answer is 10 days