A watch which gains uniformly, is 6 min. slow at 8 o'clock in the morning Sunday and it is 6 min. 48 sec. fast at 8 p.m. on following Sunday. When was it correct? Choices
A) 20 min past 7 pm on Tuesday  B) 20 min. past 7 p.m.on Wednesday  C) 20 min. past 7 p.m. on Thursday  D) 20 min. past 7 p.m. on Friday  E) None of these
Explanation :   Time from 8 a.m. on Sunday to 8 p.m. on following Sunday = 7 days 12 hours = 180 hours   The watch gains (5 + 29/5) min. or 54/5 min. in 180 hrs.   Now 54/5 min. are gained in 180 hrs.   5 min. are gained in (180 x 5/54 x 5) hrs = 83 hrs 20 min. = 3 days 11 hrs 20 min.   Watch is correct 3 days 11 hrs 20 min. after 8 a.m. of Sunday.   It will be correct at 20 min. past 7 p.m. on Wednesday.   Answer : 20 min. past 7 p.m.on Wednesday
<result>B</result>
A watch which gains uniformly, is 6 min. slow at 8 o'clock in the morning Sunday and it is 6 min. 48 sec. fast at 8 p.m. on following Sunday. When was it correct?