Question

A clock is set right at 9 a.m. The clock gains 20 minutes in 24 hours. What will be the true time when the clock indicates 3 p.m. on the following day?

(a) 2:40 p.m.
(b) 3:00 p.m.
(c) 3:20 p.m.
(d) 3:40 p.m.

Answer 1

The true time when the clock indicates 3 p.m. on the following day is 3:40 p.m.

Step-by-step explanation:

To find the true time when the clock indicates 3 p.m. on the following day, we need to consider the amount of time the clock gains in 24 hours. The clock gains 20 minutes in 24 hours, which means it gains 20/24 minutes per hour or 20/24/60 minutes per minute. Therefore, for every minute that passes on the clock, the actual time will be 1 minute 20/24/60 minutes less.

Let's calculate the time difference from 9 a.m. (clock time) to 3 p.m. (clock time) on the following day. There are 18 hours and 6 minutes between them. The actual time difference will be 18 hours plus 18*(20/24) minutes plus 6*(20/24) minutes.

Now, we can add this time difference to 3 p.m. (clock time) to find the true time. Calculating this, we get 4:40 p.m., so the correct answer is (d) 3:40 p.m.