XAT 2016 — QA & DI Question 9
Each day on Planet M is 10 hours, each hour 60 minutes and each minute 40 seconds. The inhabitants of Planet M use 10 hour analog clock with an hour hand, a minute hand and a second hand. If one such clock shows 3 hours 42 minutes and 20 seconds in a mirror what will be the time in Planet M exactly after 5 minutes?
Answer & solution
- A
6 hours 18 minutes 20 seconds
6 hours 22 minutes 20 seconds
- C
6 hours 23 minutes 20 seconds
- D
7 hours 17 minutes 20 seconds
- E
7 hours 23 minutes 20 seconds
For hours there are 10 division and 10 and 5 are opposite to each other.
When the mirror shows 3 hours 42 minutes and 20 seconds, the hour hand is between 3 and 4.
∴ The hour hand must be between 6 and 7
For minutes there are 60 division hence 60 and 30 minute mark will be opposite each other.
In the mirror the minute hand is between 42 minute mark and 43 minute mark.
∴ The minute hand must be between 17 minute mark and 18 minute mark
For seconds there are 40 divisions hence 40 and 20 second mark will be opposite each other.
In the mirror the second hand is at 20.
∴ The second hand will be at 20.
So, the actual time must be 6 hours 17 minutes and 20 seconds
So, after five minutes, the time will be 6 hours 22 minutes and 20 seconds.
âââââââAlternately,
The sum of the time visible in the mirror and the actual time should be equal to 10:00:00 hours.
10:00:00 – 03:42:20 = 06:17:20 hours
Thus, actual time is 6 hours 17 minutes and 20 seconds.
So, after 5 minutes the time will be 6 hours 22 minutes and 20 seconds
Hence, option (b).