help please

Question

Mr. Hayes water bill for every 30 days is $16. He then put in plants and grass and an automatic sprinkler.for the next 30 days his sprinklers were on every day for 15 minutes, 4 times a day. His water bill increased to $184. For the next 30 days he will have his sprinklers on every other day and only once for 15 minutes. His water bill for 30 Days should be 

Answer 1

 

His sprinklers were on for 15 minutes, 4 times a day, for 30 days.

 

     That equates to 1 hour per day, for 30 days

 

     Since the bill increased from 16 to 184, the sprinkler contributed to additional 168 dollars ... (184 - 16)

 

     Since the sprinkler ran for 1 hour per day for 30 days,  we can divide 168 by 30 to obtain the hourly cost for running the sprinkler,

 

         168 ÷ 30 = 5.60 dollars per hour

 

     To determine the cost for every other day for 15 minutes ...

         

          That equates to 15 minutes for 15 days ... 15 • 15 = 225 minutes = 225/60 hours = 3.75 hours

 

          3.75 • 5.60 = 21   ... the additional cost is $21

 

The expected bill would be $16 + $21 = $37