Question

A clock gains 5 seconds for every 3 minutes. If the clock started working at 07:00 A.M. in the morning, then what will be the time in the wrong clock at 04:00 P.M. on the same day?

• A. 03:45 P.M.
• B. 04:10 P.M.
• C. 04:15 P.M.
• D. 05:00 P.M.

Hint:

When working with clocks that gain or lose time, calculate the total time gained or lost over the period and adjust accordingly.

Answer 1

The Correct Option is C

The clock gains 5 seconds for every 3 minutes, which is a gain of 1 second every 36 seconds.
From 07:00 A.M.
to 04:00 P.M.
is 9 hours, or 540 minutes.
The number of seconds gained in this time is: \[ \frac{5}{3} \times 540 = 900 \text{ seconds} = 15 \text{ minutes.} \]
Thus, the wrong time shown by the clock at 04:00 P.M.
will be 15 minutes ahead, so the correct time is 04:15 P.M.

Thus, the correct answer is 04:15 P.M.

Answer 2

The clock gains 5 seconds every 3 minutes.
We need to find the time shown by the wrong clock at 04:00 P.M. when it started at 07:00 A.M.

Step 1: Calculate total real time elapsed from 07:00 A.M. to 04:00 P.M.
From 07:00 A.M. to 04:00 P.M. is 9 hours.
In minutes, that is 9 × 60 = 540 minutes.

Step 2: Determine how many 3-minute intervals are in 540 minutes.
Number of 3-minute intervals = 540 ÷ 3 = 180 intervals.

Step 3: Calculate total gain in seconds.
Since the clock gains 5 seconds every 3 minutes,
total gain = 180 × 5 = 900 seconds.
Convert 900 seconds to minutes: 900 ÷ 60 = 15 minutes.

Step 4: Calculate the time shown by the wrong clock.
The wrong clock runs faster by 15 minutes.
So, when the real time is 04:00 P.M.,
the wrong clock shows 04:00 P.M. + 15 minutes = 04:15 P.M.

Final Answer:
The wrong clock will show 04:15 P.M. at the actual time of 04:00 P.M.