In a watch, the minute hand crosses the hour hand for the third time exactly after every 3 hr 18 min and 15 s of watch time. What is the time gained or lost by this watch in one day?
13 min 50 s lost
14 min 40 s gained
14 min 10 s lost
13 min 20 s gained
Answers
Answer:
The correct option is A.
Explanation:
In a watch that is running correct, the minute hand should cross the hour hand once in every 65 + 5/11 minutes.
So, they should ideally cross three times once in 3 x 720/11 min = 196.36 min.
But in the watch under consideration, they meet after every 3 hr, 18 min and 15 s, i.e. (3 × 60 + 18 + 15/60) min = 198.25 min.
In other words, the watch is actually losing time (as it is slower than the normal watch). Hence, when the watch elapsed 198.25 min, it actually should have elapsed 196.36 min. So in a day, when watch will elapse (60 × 24) = 1440, it should actually elapse (1440 x 196.36/198.25) = 1426.27.
Hence, the amount of time lost in one day = (1440 - 1426.27) = 13.73, i.e. 13 min and 50 s (approximately).
Answer:
Explanation:
If a man cycles at 10 km/hr, then he arrives at a certain place at 1 PM. If he cycles at 15 km/hr, he will arrive at the same place at 11 AM. At what speed must he cycle to get there at noon?