Suppose you have a 12-hour digital clock
where the number representing the hour is
always the same as the number representing
the minute. That is, the clock can only show
times like 8:08, 9:09, 10:10, etc. What is the
smallest time difference between two such
times ?
(1) 101 minutes
(2) 61 minutes
(3) 60 minutes
(4) 49 minutes
Answers
Answer
Smallest difference is between 12:12 and 1:01 which is 49 minutes.
Hence Option (4) is correct
The right option for this question is option 4: 49 minutes
Given:
12-hour digital clock
The digital clock shows timing as:
1:01
2:02
3:03
4:04
5:05
6:06
7:07
8:08
9:09
10:10
11:11
12:12
To find:
Smallest difference between the two such times=?
Solution:
The find the smallest difference between time interval we need to calculate difference between all time intervals.
=> Difference between 1:01 and 2:02
= 60 minutes + 1 minute = 61 minutes
=> Difference between 2:02 and 3:03
= 60 minutes + 1 minute = 61 minutes
=> Difference between 3:03 and 4:04
= 60 minutes + 1 minute = 61 minutes
=> Difference between 4:04 and 5:05
= 60 minutes + 1 minute = 61 minutes
=> Difference between 5:05 and 6:06
= 60 minutes + 1 minute = 61 minutes
=> Difference between 6:06 and 7:07
= 60 minutes + 1 minute = 61 minutes
=> Difference between 7:07 and 8:08
= 60 minutes + 1 minute = 61 minutes
=> Difference between 8:08 and 9:09
= 60 minutes + 1 minute = 61 minutes
=> Difference between 9:09 and 10:10
= 60 minutes + 1 minute = 61 minutes
=> Difference between 10:10 and 11:11
= 60 minutes + 1 minute = 61 minutes
=> Difference between 11:11 and 12:12
= 60 minutes + 1 minute = 61 minutes
=> Difference between 12:12 and 1:01
= 12:12 to 1:12 = 60 minutes
= 12 minutes - 1 minute = 11 minutes
= 60 minutes = 11 minutes
= 49 minutes
Hence, 49 minutes is the smallest difference between two such times that is 12:12 and 1:10.