A clock becomes fast by 15 seconds 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.?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 9 : 02 A.M.
The clock gains at a steady rate, so its gain grows in proportion to the time passed; it was set correct at 5 P.M. on Sunday, so the gain starts from zero there.
From 5 P.M. on Sunday to 9 A.M. on Monday: 16 hours
16 hours make 8 periods of 2 hours, each adding 15 seconds
Gain \(=8\times15=120\) seconds \(=2\) minutes
So at the real 9 A.M. the clock shows 9 : 02 A.M.