Reasoning — Clock

8 mins
Time
10
Questions
🎓
1
Per Q

Read the following instructions carefully:

Select Language / भाषा चुनें
You can change language during quiz too / परीक्षा के दौरान भी बदल सकते हैं
Reasoning — Clock — Questions with Answers Open after you finish the quiz — all 10 questions, with answers and explanations.
Q1. What is the angle between the hour hand and the minute hand of a clock at 3:30?
  1. 75°
  2. 80°
  3. 65°
  4. 90°
Show answer
Answer: A. 75°
At 3:30, the hour hand is between 3 and 4, and the minute hand is at 6. Angle of minute hand from 12 = 30 minutes * 6°/minute = 180°. Angle of hour hand from 12 = 3 hours * 30°/hour + 30 minutes * 0.5°/minute = 90° + 15° = 105°. The angle between them = |180° - 105°| = 75°. Alternatively, using the formula: Angle = |(11/2)M - 30H| = |(11/2)*30 - 30*3| = |11*15 - 90| = |165 - 90| = 75°.
Q2. If a clock shows 7:20, what time will its mirror image show?
  1. 4:40
  2. 5:40
  3. 4:20
  4. 5:20
Show answer
Answer: A. 4:40
To find the mirror image time, subtract the given time from 11:60. 11:60 - 7:20 = 4:40.
Q3. How many times do the hour hand and the minute hand of a clock coincide (overlap) in a 12-hour period?
  1. 11
  2. 12
  3. 22
  4. 24
Show answer
Answer: A. 11
The hands of a clock coincide 11 times in 12 hours. They coincide once every hour, except between 11 and 1 o'clock, where they coincide only once (at 12 o'clock).
Q4. A clock gains 10 seconds every hour. If it is set right at 8 AM on Monday, what time will it show at 8 AM on Wednesday?
  1. 8:08 AM
  2. 8:04 AM
  3. 7:52 AM
  4. 8:16 AM
Show answer
Answer: A. 8:08 AM
The total duration from Monday 8 AM to Wednesday 8 AM is 48 hours. In 1 hour, the clock gains 10 seconds. In 48 hours, the clock will gain = 48 * 10 seconds = 480 seconds. Convert seconds to minutes: 480 seconds / 60 seconds/minute = 8 minutes. So, when the actual time is 8 AM on Wednesday, the faulty clock will show 8 minutes past 8 AM, i.e., 8:08 AM.
Q5. At what time between 4 and 5 o'clock will the hands of a clock be at a right angle (90 degrees)?
  1. 4:05 5/11 minutes
  2. 4:30 minutes
  3. 4:45 minutes
  4. 4:50 5/11 minutes
Show answer
Answer: A. 4:05 5/11 minutes
The formula for the angle between hands is θ = |(11/2)M - 30H|. Here, H = 4, θ = 90°. 90 = |(11/2)M - 30*4| 90 = |(11/2)M - 120| Case 1: (11/2)M - 120 = 90 (11/2)M = 210 M = 420/11 = 38 2/11 minutes. Case 2: (11/2)M - 120 = -90 (11/2)M = 30 M = 60/11 = 5 5/11 minutes. Both 4:05 5/11 minutes and 4:38 2/11 minutes are valid times. From the options, 4:05 5/11 minutes is present.
Q6. What is the smaller angle between the hour hand and the minute hand of a clock at 10:10?
  1. 115°
  2. 120°
  3. 110°
  4. 105°
Show answer
Answer: A. 115°
At 10:10, H=10, M=10. Angle = |(11/2)M - 30H| = |(11/2)*10 - 30*10| = |55 - 300| = |-245| = 245°. Since the question asks for the smaller angle, we subtract this from 360°. Smaller angle = 360° - 245° = 115°.
Q7. How many times do the hour hand and the minute hand of a clock point in opposite directions (180 degrees) in a 24-hour period?
  1. 22
  2. 24
  3. 11
  4. 23
Show answer
Answer: A. 22
The hands of a clock point in opposite directions (180 degrees) 11 times in a 12-hour period. This happens once every hour, except between 5 and 7 o'clock, where it happens only once (at 6 o'clock). Therefore, in a 24-hour period, they will point in opposite directions 11 * 2 = 22 times.
Q8. A clock gains 15 minutes in every 24 hours. If it is set right at 10 AM on Monday, when will it show the correct time again?
  1. Sunday 10 AM
  2. Saturday 10 AM
  3. Friday 10 AM
  4. Thursday 10 AM
Show answer
Answer: A. Sunday 10 AM
For the clock to show the correct time again, it must gain a total of 12 hours (720 minutes). The clock gains 15 minutes in 24 hours. Time taken to gain 1 minute = 24/15 hours. Time taken to gain 720 minutes = (24/15) * 720 hours = (8/5) * 720 hours = 8 * 144 hours = 1152 hours. Convert hours to days: 1152 hours / 24 hours/day = 48 days. So, the clock will show the correct time again 48 days after Monday 10 AM. Monday 10 AM + 48 days = Sunday 10 AM (since 48 days is 6 weeks and 6 days, Monday + 6 days = Sunday).
Q9. At what time between 5 and 6 o'clock will the minute hand be exactly 4 minutes ahead of the hour hand?
  1. 5:31 7/11 minutes
  2. 5:28 5/11 minutes
  3. 5:34 6/11 minutes
  4. 5:30 minutes
Show answer
Answer: A. 5:31 7/11 minutes
If the minute hand is 4 minutes ahead of the hour hand, the angle between them is 4 * 6° = 24°. Since the minute hand is ahead, we use the formula: (11/2)M - 30H = θ. Here, H = 5, θ = 24°. (11/2)M - 30*5 = 24 (11/2)M - 150 = 24 (11/2)M = 174 M = 348/11 = 31 7/11 minutes. So, the time is 5:31 7/11 minutes.
Q10. How many times do the hands of a clock form a right angle (90 degrees) in a 12-hour period?
  1. 22
  2. 24
  3. 11
  4. 20
Show answer
Answer: A. 22
The hands of a clock form a right angle (90 degrees) twice every hour, except between 2-3 o'clock and 8-9 o'clock, where they form a right angle only once each. So, in 12 hours, they form a right angle 22 times (24 - 2 = 22).
More practice: today's quiz · daily current affairs · full mock tests