Question

70.A watch which gains uniformly is 2 minutes low at noon on Monday and is 4 min. 48 sec fast at 2 p.m. on the following Monday. When was it correct?

• A. (a) 2 p.m. on Tuesday
• B. (b) 2 p.m. on Wednesday
• C. (c) 3 p.m. on Thursday
• D. (d) 1 p.m. on Friday

Answer 1

The correct option is B

(b) 2 p.m. on Wednesday

Ans70.(b)
Explanation:
Time from 12 p.m. on Monday to 2 p.m. on the following Monday = 7 days 2 hours = 170 hours.
The watch gains (2+4(4/5)) min or 34/5 min in 170 hrs
Now, 34/5 min are gained in 170 hrs
2 min are gained in (170*5/34*2) hrs = 50 hrs
Watch is correct 2 days 2 hrs. after 12 p m on Monday i.e., it will be correct at 2 p.m. on Wednesday