Question

17. A watch gains uniformly. It was observed that it is 5 minutes slow at 12.00 AM on Sunday. On Thursday at 6 pm, it was 5 min 48 second fast. When was it correct?

• A. (a) 4:40 PM Monday
• B. (b) 5:40 PM Monday
• C. (c) 4:40 PM Tuesday
• D. (d) 5:40 PM Tuesday

Answer 1

The correct option is B (b) 5:40 PM Monday

Ans: (b)

Sol: The time between 12AM on Sunday and 6PM on Thursday =72+18=90hours. The time gained =5+5 minutes =54/5minutes. If in 90 hrs, 54/5 minutes are gained, the time taken to gain 5 minutes =
T=90 =41hrs.
41hrs40min =24hrs+17hrs40min =1day+17hrs40min. i.e. on Monday5:40PM.