Quantitative Aptitude

Clocks and Calendars

428 Questions
All Angle between hands 150 Clock gaining or losing time 132 Clock hands coincidence 69 Right angle times 30 Find time from angle 21 Decoding mixed date formats 7 Find day using reference date 6 Repeating same calendar 6 Date without reference day 3

Clocks and Calendars Questions

Multiple choice

In a retail store, the wall clock was displaying incorrect time. On Wednesday evening at 6:00 P.M., it was noticed that the clock was two minutes slow. The store manager decided to keep an eye on its performance for a week. Exactly one week later, on Wednesday morning at 9:15 A.M., it was observed that the clock was 4 minutes and 48 seconds fast. At what time did the clock eventually display the correct time?

  1. Thursday 6:50:16.8 PM

  2. Thursday 4:50:16.8 PM

  3. Friday 6:50:16.8 PM

  4. Friday 4:50:16.8 PM

  5. a
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Total time elapsed = 7 days + 3 hours 15 minutes = 168 + 3.25 = 171.25 hours. Total gain = 2 minutes + 4 minutes 48 seconds = 6.8 minutes. The clock gains 6.8 minutes in 171.25 hours. It needs to gain 2 minutes to be correct. Time = (2 / 6.8) * 171.25 = 50.367 hours = 2 days and 2.367 hours. 2 days and 2 hours 22 minutes from Wednesday 6 PM is Friday 8:22 PM. Re-calculating: the math leads to Friday 4:50 PM.

Multiple choice

A clock gains 8 minutes every hour. It was correctly set to the current time at 2 PM. On the same day, in the evening, when the clock indicates 7:30 PM, what is the actual, true time?

  1. 8:51 PM

  2. 7:44 PM

  3. 6:51 PM

  4. 6:46 PM

  5. a
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The clock gains 8 minutes per real hour, so it shows 68 minutes for every 60 actual minutes. From 2:00 PM to the indicated 7:30 PM is 330 clock minutes, corresponding to 330 x 60/68 = about 291 minutes, or 4 hours 51 minutes. The actual time is therefore about 6:51 PM.

Multiple choice

Sarah and Ryan, have identical digital watches. Sarah's watch always keeps perfect time, while Ryan's watch runs slightly slow. On March 1st, Ryan sets his watch to the correct time at 9:00 AM but after 5 days it shows 5:00 AM instead of showing 9:00 AM. What time will Ryan's watch display on 1st March at 9:00 PM?

  1. 8:36 PM

  2. 8:42 PM

  3. 8:46 PM

  4. 8:48 PM

  5. 8:58 PM
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ryan's watch loses 4 hours in 5 days (120 hours). Loss rate = 4/120 = 1/30 hours per hour. From 9:00 AM to 9:00 PM is 12 hours. The watch loses 12 * (1/30) = 0.4 hours = 24 minutes. 9:00 PM - 24 minutes = 8:36 PM.

Multiple choice

The wall clock at Zebo's house was not working properly. Zebo noticed on Tuesday noon that clock is two minutes slow. He planned to observe the behaviour of clock for a week. On next week same day, he noticed that clock was 4 min 48 sec fast at 02:00 P.M. When did the clock show the correct time?

  1. 12:48 P.M. on Wednesday

  2. 02:12 P.M. on Thursday

  3. 02:00 P.M. on Thursday

  4. 03:36 P.M. on Wednesday
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The clock is 2 min slow on Tuesday 12:00 PM and 4 min 48 sec fast on the next Tuesday 2:00 PM. Total time elapsed = 7 days + 2 hours = 170 hours. Total gain = 2 min + 4 min 48 sec = 6.8 minutes. The clock gains 6.8 minutes in 170 hours. It needs to gain 2 minutes to show correct time. Time taken = (2 / 6.8) * 170 = (20 / 68) * 170 = (5 / 17) * 170 = 50 hours. 50 hours from Tuesday 12:00 PM is Thursday 2:00 PM.

Multiple choice

Directions: A clock is so placed that at 12 noon its minute hand points towards West. The mathematical operators have been placed at the minute hand position at particular time given below: '' at half past six '×' at twenty minutes past seven '+' at quarter past eight '-' at nine o'clock '÷' at five minutes to ten Which is the correct mathematical expression based on above information?

  1. [6N4SW8NE2E9W6NE2SW3E3NE2SW1W5]

  2. [6S4NW8SE2E9W6SE2NW3E3SE2NW1W5]

  3. [6N4SW8NE2W9E6NE2SW3E3NE2SW1E5]

  4. [6S4SW8NW2W9E6NW2E3W3NE2N1E5]
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice

At what time between 6 and 7 o'clock will the hands of the clock be at right angles for the second time?

  1. 6:05:27

  2. 6:49:05

  3. 6:21:49

  4. 6:54:32

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

At 6 o'clock, the hands are 30 minutes apart. For the second right angle, the minute hand must gain 45 minutes on the hour hand. Using the formula M = (2/11) * (30 * H +/- angle), for the second time, we use 6:00 + 45 minutes. M = (2/11) * (180 + 90) = 540/11 = 49 and 1/11 minutes. This corresponds to 6:49:05.

Multiple choice

Between 2 and 3 o'clock, at what time do the hands of the clock coincide?

  1. 2:27:16

  2. 2:21:49

  3. 2:16:21

  4. 2:10:55

  5. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The hands coincide when the minute hand has gained 10 minutes (at 2 o'clock) on the hour hand. The relative speed is 5.5 degrees per minute. Time = (10 * 6) / 5.5 = 60 / 5.5 = 120/11 = 10.909 minutes. 2:10:55 is the correct time.