Question

A watch, which loses time uniformly, was observed to be 5 minutes fast at 8.00 p.m. on Thursday. It was noticed to be 7 minutes slow at 8.00 a.m. on the subsequent Monday. When did the watch show the correct time? 

A. 7 a.m. on Saturday 

B. 7 a.m. on Friday 

C. 10 a.m. on Sunday 

D. 11 a.m. on Friday

Answer 1

Correct option: A. 7 a.m. on Saturday

Explanation: 

The number of hours from 8:00 p.m. on Thursday to 8:00 a.m. on Monday is 84. In 84 hours, the watch lost 12 minutes. But to show the correct time, the watch has to lose 5 minutes. This would happen in 5/12 x 84 = 35 hours. 35 hours from 8:00 p.m. on Thursday is 7:00 a.m. on Saturday.