Question

A watch which gains uniformly is 2 minutes slow 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

Answer: (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.

The Watch gains $(2+4\frac{4}{5})$ min. or $\frac{34}{5}$ min. in 170 hrs.

Now, $\frac{34}{5}$min. are gained in 170 hrs.

2 min.are gained in$(170\times \frac{5}{34}\times 2)$ 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