After how many hours is option a better than b

Question

Your babysitter job offers 

A.  $50 per day 

B.  $25 plus $8 per hour 

C.  $12 per hour 

Answer 1

The cutoff time is:

 

50 = 25 + 8X

 

25 = 8X

 

X = 25/8 = 3 and 1/8 hr = 3.125 hr = 3 hours 7 minutes and 30 seconds

 

Note at 3 hours, option b will pay 25 + 3 * 8 = 25 +24 = 49 < 50 = A

So if the job is LONGER than the cutoff time shown above in BOLD, then

choose option B. Otherwise option A is better