Pete worked 4 hours and charged Millie 170. Rosalee called​ Pete, he worked 7 hours and charged 230. If​ Pete's charge is a linear function of the number of hours​ worked, find the formula for​ Pete's rate, and how much he would charge for working 8 hour?

1 Answer
May 13, 2018

Formula is #$20xxh+$90#, where #h# is number of hours for which Pete works. He would charge #$250# for working #8# hour.

Explanation:

When Pete worked #4# hours and charged Millie #$170#

and when he worked #7# hours and charged Millie #$230#

Hence for extra #3# hours he charged #$230-$170=$60#

As relation between charge and number of hours worked is linear (one can say proportional)

He charged #$60/3=$20# per hour.

However, this mean for #4# hours he should charge #$20xx4=$80#, but he charged #$170#

Hence it is apparent that he charges #$170-$80=$90# as fixed charge over and above #$80#

Hence formula is #$20xxh+$90#, where #h# is number of hours he works.

Therefore for #8# hours he would charge #$20xx8+$90# or #$160+90=$250#