Elitmus
Exam
Numerical Ability
Clocks and Calendars
There are 36 hours in a day, 90 minutes in an hour and 60 seconds in one minute. What is the angle between hour hand and minute hand when time is 15:50?
Read Solution (Total 12)
-
- Hour hand speed = 360/(18*90) =2/9 DPM
Minute hand speed =360/90 = 4 DPM
Now 18 hours have 360 degree
then 1 hour has 360/18= 20 degree
so 15 * 20 make 300 degree
hour hand = 300 + 50 * 2/9 =311.10 degree
minute hand = 50 * 4= 200 degree
here is the difference 311.10-200= 111.10 degree
- 8 years agoHelpfull: Yes(28) No(0)
- 24 hours 36 hours
-----------------------------------------------------------------------------------
24hrs/2=12points on the clock 36 hrs/2=18 points on the clock
60mins/12points=5mins for each point 90mins/18 points=5 mins for each point
Now to find the angle betwen hour hand and minute at 15:50
At 15:00
hour hand---->(15/18)*360 = 300 degrees
minute hand----> 0 degrees
so angle between hour and minute hand = 300-0=300 degrees
at 15:50
hour hand----->300 + (50/90) *20 where20 is the angle per point (360degree/18 points)
= 300 + (100/9)
minute hand----->(50/90) * 360 =200
so the angle between hour and minute hand = (300 + (100/9)) -200
= 2800/9 - 200
= 2800/9 -1800/9
= 1000/9 degrees (or) 111.1 degrees - 8 years agoHelpfull: Yes(19) No(3)
- 1 day=36 hrs
1/2 days=18 hrs
18 hrs=360 deg
convert it in terms of min
18*90 min=1620 min
1620 min=360 deg
1 min=(2/9) deg
For min hand:
90 min=360 deg
1 min=4 deg
angle btwn H and M=2/9(H*90 + M) - 4*M
=20*H - (34*M)/9
put value of hr and min we get
=20*15 -(34*50)/9
=111.1 deg
- 8 years agoHelpfull: Yes(6) No(0)
- movement of hour hand per hour = 360/18= 20 degree
movement of hour hand per minute = 20/90 = 2/9 degree
angle made by hour hand at exact 15 hours = 360*15/18 = 300 degree
In 50 minutes hour hand will move = 50 * 2/9 = 100/9 = 11.11 degree
so total angle of hour hand when minute hand is at 50 minutes = 300+ 11.11 = 311.11 degree
angle of minute hand at 50 minutes =360* 50/90 = 200 degree
difference between them = 311.11- 200 = 111.11 degree - 8 years agoHelpfull: Yes(4) No(0)
- minute hand=50/90*360=200
hour hand=15/18*360=300
therefore, angle betwwen hour hand and minute hand=300-200=100 - 8 years agoHelpfull: Yes(3) No(9)
- 311.11- 200 = 111.11 degree
- 8 years agoHelpfull: Yes(2) No(0)
- 15:00 ---> hour hand---->(15/18)*360 = 300 degrees
15:50 --> hour hand----->300 + (50/90) *20
angle between hour and minute hand = (300 + (100/9)) -200 ==111.1
- 8 years agoHelpfull: Yes(1) No(0)
- 100 degrees
- 8 years agoHelpfull: Yes(0) No(5)
- min hand=50*360/90=200
hour hand=15*360/36=150
angle=200-150=50(ans) - 8 years agoHelpfull: Yes(0) No(4)
- The answer will be 148.5 degrees
- 8 years agoHelpfull: Yes(0) No(4)
- 1day = 36 h
angle at 1 h = 360/36 = 10 degree
angle at 1m for hour hand = 10/90 = 1/9 degree
total angel of hour hand at 15:50 = 15*10+50*1/9=155.56 degree
Now angle for minute hand
angle at 1 m = 360/90 =4 degree
at 50 minute angel will be = 50*4=200 degree
now angle between them = 200-155.56 = 44.44 degree
please correct if I made mistake - 8 years agoHelpfull: Yes(0) No(1)
- i think we should consider 60 seconds in 1 minute, so then clock will contains 1.5,3,4.5.....18. in place of normal clock's 1,2,3,..12 and 1.5,3,4.5....90 in place of 1,2,3,...60 as minutes.In question given the angle between 15:50 means approximately 10:33 in normal clock. then the angle will be 136.5 for 15:50.
- 8 years agoHelpfull: Yes(0) No(0)
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