Piyush Dixit MCA 4 years of teaching experience for Competitive Exams

Clock Chapter-3 160' IO 9 8 2 3 7 LIVE YOURLIFEBYA COMPASSNOTA CLOCK

Q. At what time between 6 to 7, 90 angle will be formed? First Method Angle +/(30H-11/2*M) Since as we know that 90 degree angle will be formed twice so this time we will take both 12 positive and negative value of expression in bracket 90 +/-(30*6-11/2*M) By taking positive sign -> 90 = 180-1 1/2*M-> 11*M = 180 Hence Minute is equal to 180/11 or 16(4/11) By taking negative sign >90 (-180 +11/2*M) -> 11*M 540 Hence Minute is equal to 540/11 or 49(1/11) So Our Answer will be 6:16 (4/11) And 6:49 (1/11) 4

12 Q. At what time between 6 to 7, 90 angle will be formed? Second Method: As it is obvious that in order to be the 90 angle the difference between hour and minute hand should be 15 minutes: First Case: when hour hand at 6 and minute hand at 3 So travelled distance is 15 hence -> 15*12/11 180/11 Second Case: when hour hand at 6 and minute hand at 9 So travelled distance is 45 hence -> 45*12/11 540/11 So Our Answer will be 6:16 (4/11) And 6: 49 (1/11) 4

Q. When will be the first time post 9 there will be 90 degree angle will be made?

Now we will deal some other type of questions from Clock topic

Q. If in a clock time is 6:20 and minute hand is indicating towards North -East direction, then in which direction hour hand is facing A) South C) East B) North D) West 12 0 2 3 North 4 N-E West _- East South

Q. From new Delhi railway station, there is train for Kanpur in every 2:30 hour. There is an announcement that train for Kanpur has moved before 40 minutes and the next train will be at 18:00 o'clock, then find out by what time this announcement was made? A) 15:30 C) 16:10 B) 15:50 D) 16:30 (18:00) (2:30) 15:30 hours 15:30+00:40 16:10

Q. A clock is 5 minute slow at 6 am on a Monday, on subsequent Wednesday at 6 pm it is 10 minutes fast then find out when this clock showed the right time A) 2 am Tuesday C) 6 am Tuesday B) 4 am Tuesday D)1 am Wednesday From 5 Minute slow to 10 minute fast -> 15 minute time difference From 6 am Monday to 6 pm Wednesday (24+24+12) 60 hours 15 minute time difference in 60 hour Since clock is 5 minute slow, so we need to see that time will be covered in 20 hours hence our answer will be 6 am Monday+ 20 hours - 2 am Tuesday

Q. A clock takes 33 second in echoing 12 times. How much time does it take to echo 7 times? A) 21 Second C) 19.25 Second D) None of these Easy and tricky question, Before solving this question you need to tell B) 18 Second that how many cuts are needed to make 4 equal pieces of a rope Similarly for echoing 11 times 33 second are needed so for echoing one time 3 second are needed Similarly for echoing 7 times, it needs to be echoed 6 interval of time hence 6*3 18 second

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Piyush Dixit

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Roshan kumar

a year ago

awesome sir..

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Aansh Agarwal

7 months ago

I have a doubt on the question of direction of the hour hand after 6. The hour hand will reach 6 i.e., south direction so in order to move the hour hand in south east direction or east direction he time has to be less than 6?? As after 6 the hour hand will remain in south direction unless the hour changes from 6 to 5 or so..?

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Aansh Agarwal

7 months ago

Is the answer 9:32(8/11) ??

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Aansh Agarwal

7 months ago

I've done this by taking it +ve as while taking it -ve the answer is 9:65(5/11) but it's 65 so it'll become 10:05(5/11) as e hour changes. So what shall be considered here?

Riya

a year ago

Sir, all your lessons are too good n very helpful... N easy to understand also

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Piyush Dixit

a year ago

Thanks