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

Two clocks were set in the morning at 10 a.m. on Sunday. One clock loses 3 minutes in an hour, while the other gains 2 minutes in an hour. By how many minutes do the two clocks differ in the evening at 4 p.m. on the same day?

  1. 25 minutes

  2. 20 minutes

  3. 35 minutes

  4. 30 minutes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

From 10 a.m. to 4 p.m. is 6 hours. One clock loses 3 min/hr (total loss 18 min), the other gains 2 min/hr (total gain 12 min). The difference is 18 + 12 = 30 minutes.

Multiple choice

An antique clock which gains time uniformly is 10 minutes slow at 9:00 a.m. on Monday morning and 10 min 48 sec fast at 9:00 p.m. on the following Monday. When did it show the correct time during the intervening period?

  1. At 11:00 p.m. on Wednesday

  2. At 11:32 p.m. on Thursday

  3. At 11:40 p.m. on Wednesday

  4. At 11:28 p.m. on Thursday
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total time from Monday 9 AM to next Monday 9 PM is 7 days + 12 hours = 180 hours. The clock gains 10 min + 10 min 48 sec = 20.8 minutes in 180 hours. It needs to gain 10 minutes to show the correct time. Time taken = (10 / 20.8) * 180 = 86.538 hours = 3 days 14 hours 32 minutes. Adding this to Monday 9 AM gives Thursday 11:32 PM.

Multiple choice

Consider a clock hanging on the wall of your room. You noticed that the hour hand of the clock is between 2 and 3 and the minute hand is on 3. Now, what will be the angle formed between both the hands?

  1. 22°

  2. 22.5°

  3. 157.5°

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

Minute hand at 3 means 15 minutes. Hour hand between 2 and 3 means it has moved 15/60 * 30 degrees = 7.5 degrees from the 2 o'clock position. The angle between 2 and 3 is 30 degrees. Angle = 30 - 7.5 = 22.5 degrees.

Multiple choice

A watch, which gains uniformly, is 3 minutes slow at 12 noon on Monday and is 5 minutes 36 seconds fast at 4 pm on the next Monday. At what time it was showing correct time?

  1. 12 am on Tuesday

  2. 12 pm on Wednesday

  3. 12 am on Thursday

  4. 12 pm on Thursday
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Total time = 7 days + 4 hours = 172 hours. Total gain = 3 min + 5 min 36 sec = 8.6 minutes = 516 seconds. Gain per hour = 516 / 172 = 3 seconds/hour. To correct 3 minutes (180 seconds), time = 180 / 3 = 60 hours. 60 hours = 2 days and 12 hours. Monday 12 noon + 2 days 12 hours = Thursday 12 am.

Multiple choice

What is the chance that a leap year, selected at random, will contain 53 Sundays?

  1. 2/7

  2. 3/7

  3. 1/7

  4. 5/7
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A leap year has 366 days, which is 52 weeks and 2 extra days. The possible pairs for these 2 extra days are (Sun, Mon), (Mon, Tue), (Tue, Wed), (Wed, Thu), (Thu, Fri), (Fri, Sat), or (Sat, Sun). Out of these 7 equally likely outcomes, 2 contain a Sunday, resulting in a probability of 2/7.

Multiple choice

At what time will a right angle be formed by the two hands in a clock before 10 O’clock?

  1. Data inadequate

  2. 9:00

  3. will not be formed

  4. 9:30

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

A right angle (90 degrees) is formed when the hour and minute hands are 15 minutes apart. Before 10 o'clock, the two right angles occur at approximately 9:00 and 9:33. The question asks for 'before 10 O'clock' and 9:00 is one of the exact times when a right angle is formed.