## Aptitude Clocks Test Paper 26) A clock is set at 4am. It loses 16 minutes in 24 hours. What will be the correct time when the clock indicates 9pm on the 4th day? - 8pm
- 7pm
- 10pm
- 11pm
The Correct time is (C)
Time from 4am on a day to 9pm on the 4 As per the question, 23 hrs 44 minutes of this clock = 24 hours of the correct clock as this clock loses 16 minutes in 24 hours. 23 hrs 44 minutes = Now, Hrs of this clock = 24 hours of correct clock 89 hours of this clock = * 89 = 90 hours of the correct clock, i.e. the correct clock gains one hour over the incorrect clock. ∴The correct time on the fourth day would be 10pm. 7) How much does a watch lose per day, if its hands coincide every 63 minutes? - 56min.
- 57min.
- 55min.
- 54min.
The Correct answer is (A)
The hands of a clock coincide once after 65 minutes in every hour. As per question, the hands coincide in every 63 minutes. Therefore, the loss in 63 minutes = Now, loss in 63 minutes = ∴ Loss per day or in 24 hours= 8) At what time between 4:30 and 5:00 will the hands of a clock be at right angle? - 35min. past 4
- 37min. past 4
- 38min. past 4
- 39min. past 4
The Correct answer is (C)
As we know, the hands of a clock will be at 90° between H: 30 and (H+1) O'clock at (5H + 15) minutes past H O' clock. ∴ Required time = (5H + 15) Now, H = 4 = (5*4 + 15) 9) A watch which gains uniformly is 5 minutes slow at 6am on Monday and is 5 minutes 48 seconds fast at 6pm on the following Monday. When was it correct? - 5:20 pm on Wednesday
- 5:20 pm on Thursday
- 4:20 pm on Wednesday
- 4:20 pm on Thursday
The Correct answer is (B)
Time from 6am on Monday to 6pm on following Monday = 7 days and 12 hours, i.e. 24*7 + 12 = 180 hours So, the watch gains minutes in 180 hours Now, minutes are gained in 180 hours ∴ 5 minutes will be gained in hours or 83 hours 20 minutes. 83 hour 20 minutes = 3 days (72 hours) 11 hours 20 minutes Therefore, the watch was correct 3 days 11 hours 20 minutes after 6am on Monday, i.e. it was correct at 20 minutes past 5pm on Thursday. 10) At what times between 5 O' clock and 6 O' clock the hands of a clock are 10 minute spaces apart? The Correct answer is (A)
Between 5 O' clock and 6 O' clock, the hands will be 10 minutes spaces apart twice, i.e. when the minute hand is 10 minute spaces behind the hour hand and when the minute hand is 10 minute space ahead of the hour hand.
At 5 O' clock, the minute hand is 25 minute spaces behind the hour hand. So, the minute hand has to gain (25-10) = 15 minute spaces over hour hand to be 10 minute spaces apart. Now, 55 minute spaces are gained in 60 minutes. 15 minute spaces will be gained in * 15 = 16 minutes ∴The hands of the clock will be 10 minute spaces apart at 16 minutes past 5.
The minute hand has to gain (25 + 10) = 35 minute spaces over the hour hand. Now, 55 minutes are gained in 60 minutes. 35 minutes will be gained in * 35 = 38 minutes ∴ The hands of the clock will be 10 minute spaces apart at 38minutes past 5. Aptitude Clocks Test Paper 1 Aptitude Clocks Test Paper 2 Clocks Concepts |