Question

A clock becomes fast by 15 second in every 2 hours. If it is set correct at 5 P.M. on Sunday, what will be the time on clock on Monday at 9 A.M. ?

• A. 9 : 02 A.M.
• B. 9 : 03 A.M.
• C. 9 : 04 A.M.
• D. 9 : 05 A.M.

Hint:

16 hours pass, so the clock gains 8 x 15 s = 120 s = 2 min.

Answer 1

The Correct Option is A

Step 1: Understanding the Question
The clock gains 15 seconds for every 2 hours of real time. It is right at 5 P.M. on Sunday. We need the time it shows at 9 A.M. on Monday.

Step 2: Find the real time passed
From 5 P.M. Sunday to 5 A.M. Monday is 12 hours. From 5 A.M. to 9 A.M. is 4 more hours. The total is 16 hours.

Step 3: Find the number of 2-hour blocks
\[ \frac{16}{2} = 8 \]
So there are 8 blocks of 2 hours.

Step 4: Find the total time gained
\[ 8 \times 15 = 120 \text{ seconds} = 2 \text{ minutes} \]

Step 5: Find the time on the clock
The clock is ahead by 2 minutes. When the real time is 9:00 A.M., the clock shows 9:02 A.M.

Step 6: Check the other options
9:03 would need 180 seconds, that is 12 blocks or 24 hours. 9:04 and 9:05 need even more. These do not fit 16 hours.

Final Answer:
The clock shows 9:02 A.M., option 1. \[ \boxed{9:02 \text{ A.M.}} \]