Question

1. According to a recent survey, 13 out of the 33 students in a class take the bus to school. What is the ratio of students who take the bus to school to students who do not? Show your work and explain.

2. For every 2 red candies in a package, there are 3 green candies. How many red candies would there be if you have 12 green candies? Show your work and explain.





3. This table describes the relationship between the number of servings of pizza and the number of cups of cheese needed to prepare them.



Number of Servings of Pizza | Number of Cups of Cheese

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6 | 10

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9 | 15

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15 | 25

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A. Test to see if the ratios of pizza servings to cups of cheese are equivalent. Show your work.



B. Explain in words whether or not the relationship between the pizza servings to the cups of cheese is proportional.

Answer 1

Answer: (1) 13/20 (2) 8 (3) Yes. They are proportional

Explanation:

(1) 13 students take the bus.

33 - 13 = 20 students do not take the bus

`\frac{\text{take the bus}}{\text{do not take the bus}}:(13)/(20)`

(2)

`(2\ red)/(3\ green)=(x)/(12\ green)\\\\\\\underline{\text{cross multiply}:}\\2(12)=3(x)\\24=3x\\8=x`

(3)

`(6)/(10)/ (2)/(2)\quad =(3)/(5)\\\\\\(9)/(15)/ (3)/(3)\quad =(3)/(5)\\\\\\(15)/(25)/ (5)/(5)\quad =(3)/(5)`

All of the fractions simplify to the same number so they ARE proportional.