+0  
 
+1
32
1
avatar

For what fraction of a day wil a 12 hour digital clock that shows only the hours and minutes display at least one 5 or 6

Guest Nov 24, 2018
edited by Guest  Nov 24, 2018

Best Answer 

 #1
avatar+3152 
+1

from 5:00 - 6:59 there will be a 5 or 6 visible at all times

 

from H:50 - H:59 there will be a 5 visible at all times, 1<= H <= 4 and 7 <= H <= 12

 

from H:M5 - H:M7 there will be a 5 or 6 visible at all times, 1 <= H <= 4 and 7<= H <= 12, 0 <= M <= 4

 

Summing all this up

 

2 hrs = 120 minutes for the first category

 

10 minutes apiece of 10 hrs = 100 min for the second category

 

2 minutes 5 times an hr for 10 hrs = 100 minutes

 

So a total of 320 minutes out of a total of 12 x 60 = 720 minutes

 

p = 320/720 = 4/9

Rom  Nov 24, 2018
 #1
avatar+3152 
+1
Best Answer

from 5:00 - 6:59 there will be a 5 or 6 visible at all times

 

from H:50 - H:59 there will be a 5 visible at all times, 1<= H <= 4 and 7 <= H <= 12

 

from H:M5 - H:M7 there will be a 5 or 6 visible at all times, 1 <= H <= 4 and 7<= H <= 12, 0 <= M <= 4

 

Summing all this up

 

2 hrs = 120 minutes for the first category

 

10 minutes apiece of 10 hrs = 100 min for the second category

 

2 minutes 5 times an hr for 10 hrs = 100 minutes

 

So a total of 320 minutes out of a total of 12 x 60 = 720 minutes

 

p = 320/720 = 4/9

Rom  Nov 24, 2018

10 Online Users

avatar
avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.