Ken is working this summer as part of a crew on a
farm. He earned $8 per hour for the first 10 hours he
worked this week. Because of his performance, his
crew leader raised his salary to $10 per hour for the
rest of the week. Ken saves 90% of his earnings from
each week. What is the least number of hours he
must work the rest of the week to save at least $270
for the week?
A) 38
B) 33
C) 22
D) 16

It is given that, he earns $8 for the first 10 hours of the week and his salary got increased to $10 per hour for the rest of the week. He saved 90 % of his earnings from each week.

We have to find the least number of hours he must work for the rest of the week to save atleast $270 for the week.

Let the number of hours he must work for the rest of the week to save atleast $270 for the week be h hours.

Hence, his total earnings for the week will be:-

[tex]8*10+10*h=80+10h[/tex]

As he saves 90 % of his earnings, he saved:-

[tex]\frac{90}{100}*(80+10h)[/tex]

As his savings should be atleast $270 for the week

Hence,

[tex]\frac{90}{100}*(80+10h)\geq 270\\\\80+10h\geq 270*\frac{100}{90}\\\\80+10h\geq 300\\ 10h\geq 300-80\\ 10h\geq 220\\h\geq \frac{220}{10}\\\\h\geq 22 hours[/tex]

To learn more about savings, here:-

https://brainly.com/question/7965246

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