Problems :
1) 1) Find the angle between Hour hand and minute hand of a clock when the time is 3.25 ?
Solution : Angle=|(11*m/2)-(30h)| = |(11*25/2)-(30*3)|=47.5 degrees
2) 2) At What time between 2 and 3 o’clock will hands of a clock together ?
Solution : If the Both the hands are together means angle between the clock is zero(0).Let the hour is at 2 o’clock.
Angle=|(11*m/2)-(30h)|
0=|(11m/2)-(30*2)|
11m/2=60
M=60*2/11=10 10/11 mins.
Hence the two hands are meet at 10 10/11 mins past 2.
3) Find the angle between Hour hand and minute hand of a clock when the time is 8:30 ?
Solution : Angle=|(11*m/2)-(30h)|
= |(11*30/2)-(30*8)|=|165-240|= 75 degrees
4)How many times do the hands of a clock coincide in a day ?
Solution : 22 times (Every 12 hours 11 times they are meeting)
5)At What time between 7 and 8 o’ clock will the hands of a clock be in the same straight line but not together ?
Solution : hands of a clock be in the same straight line but not together means angle is 180 degrees.
Let the hour is at 7 o’clock.
Angle=|(11*m/2)-(30h)|
180=|(11m/2)-(30*7)|
11m/2=180+210 or 11m/2=-180+210
11m/2=390 or 11m/2=30
m=780/11 or m=60/11
m= 72 8/11 or 5 5/11 mins.
Hence the time will be either 72 8/11 mins past 7or 5 5/11 mins past 7
6) A clock loses 5 min for every hour and another clock gains 5 min for every hour .If they are set correct at 10 am on Monday then when will they be 12 hrs apart ?
Solution : for every hour watch A loses 5 min and watch B gains 5 mins.
So for every hour they will differ by 10 mins.
For 12 hours (720 mins ) difference between them is =720/10 =72 mins.
So they will be 12 hrs apart after 3 days i.e: at 10 am on Thurs day
No comments:
Post a Comment