Syntel
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Numerical Ability
Clocks and Calendars
At what time between 5.30 and 6 will the hands of a clock be at right angles?
A. 478/11min. past 5
B. 480/11min. past 5
C. 40 min. past 5
D. 45 min. past 5
Read Solution (Total 3)
-
- B. 480/11min. past 5
using this formula
Apply the following formula:
11/2m-30h=90 deg ..... pls note that here h=5
then 11/2 min = 90 +30*5 = 240
min= 240*2/11 = 480/11 min past 5.... option B - 13 years agoHelpfull: Yes(10) No(2)
- At 5 o'clock, the hands are 25 min. spaces apart.
To be at right angles and that too between 5.30 and 6, the minute hand has to gain (25 + 15) = 40 min. spaces.
55 min. spaces are gained in 60 min.
40 min. spaces are gained in (60*40/55) min=480/11 min. past 5
Required time = 480/11 min. past 5. - 10 years agoHelpfull: Yes(3) No(1)
- The clock will be at right angles when the angle between the hour hand and minute hand is 90 deg.
Apply the following formula:
11/2m-30h=90 deg
(11/2)m-30*11/2=90
Solving we get m=510/11
So the clock will be at right angle when the time is 510/11 min past 5(option not given) - 13 years agoHelpfull: Yes(1) No(9)
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