Question

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. 2 p.m. on Tuesday
• B. 2 p.m. on Wednesday
• C. 3 p.m. on Thursday
• D. 1 p.m. on Friday

Answer 1

The correct option is B 2 p.m. on Wednesday

Time from 12 p.m. on Monday to 2 p.m. on the following Monday = 7 days 2 hours = 170 hours.
$\therefore Thewatch(2+4\frac{4}{5})minor\frac{34}{5}minin170hrs$
$Now,\frac{34}{5}minaregainedin170hrs$
$\therefore 2minaregainedin50hrs$
$\left(170x\frac{5}{34}x2\right)hrs$
$\therefore$ 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