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: Concept
A clock that gains a fixed amount per hour can be handled by finding the gain per hour. Then we multiply by the number of hours.

Step 2: Gain per hour
The clock gains 15 seconds in 2 hours. So per hour it gains 7.5 seconds.

Step 3: Hours between the two times
Sunday 5 P.M. to Monday 9 A.M. is 24 - 17 + 9 = 16 hours, using the 24-hour clock.

Step 4: Total gain
\[ 16 \times 7.5 = 120 \text{ seconds} \]
This equals 2 minutes.

Step 5: Final clock reading
Real time 9:00 A.M. plus 2 minutes gain gives 9:02 A.M. on the faulty clock.

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