NIMCET 2021
How many times in a day are the hands of a clock pointing opposite to each other?
Answer (Detailed Solution Below)View answer ▾Hide ▴
Answer: Option C — 22
Detailed Solution
In 12 hours the minute hand gains 11 full rounds on the hour hand, so the hands are opposite 11 times.
In 24 hours: .
✓ Check
Between 5 and 7 o'clock the hands are opposite only once, at 6:00; that shared case is why it is 11, not 12, per 12 hours.⚠ Common trap
(D) 24 assumes the hands are opposite once every hour.Quick tip
Hands are opposite 11 times in 12 hours, so 22 times a day
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Ask a doubtMore Clocks Questions
View all ›- Q1.A doctor said to his compounder, 'I go to see the patients at their residence after every 3 hours 30 minutes. I have already gone to the patient 1 hour 20 minutes ago and next time I shall go at 1:40 P.M.' At what time was this information given to the compounder by the doctor?
- Q2.Jimmy saw the time while going to the tennis court. He saw the hour hand is 20 degrees away from 4. After he returned from the tennis court, he noticed that the hour hand is 20 degrees away from 4. If he took ten minutes to go to the tennis court and he walked at the same speed while going to the tennis court and while returning, how much time did he spend at the tennis court?
- Q3.A clock is set right at 8 a.m. The clock gains minutes in hours. What will be the correct time when the clock shows 1 p.m. on the next day?
- Q4.A watch which gains seconds in minutes was set correct at 9 a.m. When the watch indicated 20 minutes past 7 o'clock the same evening, the true time is
- Q5.What is the angle between the hour hand and the minute hand of a clock at 4:20?
More Logical Reasoning Questions
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Clocks — Preparation
This question tests your understanding of Clocks, a key topic in the Logical Reasoning section. The detailed solution above uses a step-by-step approach to show the reasoning, and where available, a shortcut that helps you solve similar questions in under 90 seconds during the actual exam.
Clock questions ask about the angle between the hour and minute hands at a given time, or the times at which the hands are together, opposite each other or at right angles. The key facts are that the minute hand moves 6 degrees per minute and the hour hand moves 0.5 degrees per minute, so the minute hand gains 5.5 degrees on the hour hand every minute. The angle between the hands at H hours and M minutes is |30H - 5.5M| degrees. In 12 hours, the hands coincide 11 times, are opposite 11 times, and are at right angles 22 times. The topic also covers faulty clocks that gain or lose time, and mirror images of clocks. Learning these few formulas turns most clock questions into short calculations. Practise the clock questions below, each with a step-by-step solution.