Hello students, try solving these questions. The questions might seem easy but accuracy is the differentiaor in such types of questions.
- Two trains, one from Howrah to Patna and other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speed is:
- 2 : 03
- 4 : 03
- 6 : 07
- 9 : 06
- A watch which gains uniformly is 2 minutes slow at noon on Monday and is 4 minute 48 second fast at 2 p.m. on the following Monday. When was it correct?
- 2 p.m. on Tuesday
- 2 p.m. on Wednesday
- 3 p.m. on Thursday
- 1 p.m. on Friday
- A speaks truth in 75% cases and B in 80% cases. In what percentage of cases are they likely to contradict each other, narrating the same incident?
- Let speed of train from Howrah to Patna be ‘a’ and from Patna to Howrah be ’b’ and time taken to reach their respective destinations after meeting be T1 and T2 respectively.
a/b = (T2/T1)^(1/2)
a/b = 4/3
- Total time gained: 6 min 48 seconds = 408 seconds
Total hours elapsed = 24*7 + 2 = 170 hours
Time at which watch showed correct time = (170 hours/480 seconds) * 120 seconds = 50 hours
Therefore, after 2 days and 2 hours i.e. 2 p.m. Wednesday, watch showed correct time.
- Required answer: 0.75*0.2 + 0.25*0.8 = 0.35 or 35%
Academic Research Associate, BFactory