Question

A clock is set to show the correct time at 11:00 a.m. The clock gains 12 minutes in 12 hours. What will be the correct time when the clock indicates 5:30 p.m. the next day?
a.5:00 p.m.
b.5:10 p.m.
c.5:20 p.m.
d.4:59 p.m.
e.5:48 p.m.

Answer 1

Hint: The clock is showing the correct time at 11:00 a.m. and after that it gains 12 minutes in 12 hours. Now, from unitary method if a clock gains 12 minutes in 12 hours then the same clock will gain 1 minute in 1 hour so from 11:00 a.m. to next day 5:30 p.m. 31 hours and 30 minutes were elapsed so the clock has gained 31.5 minutes it means the actual time is the subtraction of 31.5 minutes from 5:30 p.m.

Complete step by step answer:
The clock is giving the correct time at 11:00 a.m. and after that the clock gains 12 minutes in 12 hours so we can say that the clock is gaining 1 minute in 1 hour. Now, we have to determine the correct time at 5:30 p.m. From 11:00 a.m. to 5:30 p.m., 31.5 hours are elapsed so the clock has gained 31.5 minutes. It means we have to subtract 31.5 minutes from 5:30 p.m. which will give the actual time as 4:59 p.m.
From the above discussion we have come to a conclusion that the correct time when the clock shows 5:30 p.m. is 4:59 p.m.

Hence, the correct option is d.

Note: The plausible point where you go wrong in this problem is that you could not figure out what does this statement in the question “The clock gains 12 minutes in 12 hours” mean because you might think that after 12 hours whether the clock will be slower than the usual time or it will be faster than the usual time. The clarity regarding this confusion is that the clock gains 12 minutes in 12 hours meaning if the clock would not gain 12 minutes in 12 hours then after 12 hours the clock will show 11:00 p.m. but now the clock has gained 12 minutes in 12 hours then the clock will show 11:12 p.m. so you can see that the clock becomes faster than the actual time by 12 minutes in 12 hours.