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

4/9

Step-by-step explanation:

Find out combinations without 5 or 6.

Minutes with 5 or 6: 05,06,15,16,25,26,35,36,45,46,50–59. It 10+10=20 minutes per hour. And 40 minutes without 5 or 6.

Hours with 5 or 6: 5 and 6. Without 5 and 6 is 0,1,2,3,4,7,8,9,10,11 (10 hours).

Total time without 5 and 6 is 10*40minutes=400 minutes.

Time with 5 or 6 is 12*60–400=320 minutes.

Fraction of a day: 320/(12*60)=4/9=0.44444

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is:

the monthly balance will be $75,000