Please make sure to show the work that leads to the solution of each problem. Also, it would be preferred if the solution is written on a paper.

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Chapter 7.5.1 Proportions

Chapter 7.5.1 Propor ons

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Points 8

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MAT121Chap7p5Applications.pdf

Proportion problems.

1. Find the lengths x and y in the pictured triangle.

2. Usually when making Chex mix, I use 1/2 of a can of mixed nuts and 2 cups of most of the

cereals. But I’m trying to use up one of the boxes of cereal since there’d only be a small amount

left so I’m going to use 2 and 1/2 cups of all of the cereals. How much of the can of mixed nuts

should I use to keep everything proportional?

3. The apparent brightness of a light varies inversely with the square of the distance to the light.

Standing at a distance of 20 meters, a light has a brightness of 14.38 candelas. Use this to find

$k$; and determine what the apparent brightness will be if we move to 30 meters away.

4. One US dollar was exchanging for 1.442 Australian dollar as of Saturday, Sept. 26. If someone

told you their take-home pay was 800 AUD (Austrialian dollars) every two weeks, how much

money in USD (United States dollars) is that?

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Chapter 7.5.2 Work, Travel

Chapter 7.5.2 Work, Travel

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Points 6

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MAT121Chap7p5AppsWork.pdf

Problems about cooperation and travel.

1. Each semester, Mary and Sam have to put new batteries into all of the spare calculators that are

available for checkout at the testing center. It takes Mary 18 minutes to do that, and it takes Sam

22 minutes, if they are working alone. This year, they’re told to hurry up and work together to get

it done. How long should we expect it to take?

2. A hose is filling a hot tub, but there’s a leak in the filter system. Normally it takes the hose 35

minutes to fill the hot tub, but today it took 40 minutes because the leak was working against the

hose (the rates won’t add, they’ll subtract!) How long will it take the leak to completely empty the

pool?

3. A slow moving group starts at one end of a circular trail; another group that moves 3 mph faster

goes the other way around, leaving at the same time, and when they meet, the slow group has

gone 2 miles while the faster group has gone 4 in the same amount of time. How fast is each

group moving?

4. A short video question.

It may be a bonus!

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Chapter 7.5.2 Work, Travel

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Chapter 8.1 Radicals

Chapter 8.1 Radicals

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Points 10

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MAT121Chap8p1.pdf

The beginning of the chapter about radicals.

1.

Do we need absolute value bars? If the instructions say “Assume all variables represent

positive quantities”, then we don’t.

2.

(Does it need absolute value bars?)

3.

Is it real?

4.

Is it real?

5.

Try not to use a calculator.

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