Let's solve each problem step by step.
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Problem 1: Who eats more chips in 3 hours?
We are given:
- A graph showing
Rebecca’s chip-eating rate.
- An equation for
Leila: $ y = 15x $, where:
- $ x $ = number of hours
- $ y $ = number of chips eaten
We need to find out
who eats more chips in 3 hours.
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Step 1: Find how many chips Rebecca eats in 3 hours
Look at the graph for Rebecca:
- The graph is a straight line passing through points like:
- (1, 12)
- (2, 24)
- (3, 36)
- (4, 48)
- (5, 60)
So, at $ x = 3 $ hours, $ y = 36 $ chips.
✔ Rebecca eats 36 chips in 3 hours.
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Step 2: Find how many chips Leila eats in 3 hours
Use the equation:
$ y = 15x $
Plug in $ x = 3 $:
$$
y = 15 \times 3 = 45
$$
✔ Leila eats 45 chips in 3 hours.
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Compare:
- Rebecca: 36 chips
- Leila: 45 chips
👉
Leila eats more chips in 3 hours.
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✔ Answer to Problem 1:
Leila eats more chips in 3 hours.
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Problem 2: Who uses sugar at a faster rate?
We are given:
- A graph for
Erin, showing number of cups of tea vs. pounds of sugar used.
- An equation for
Lucia: $ y = 10x $, where:
- $ x $ = pounds of sugar
- $ y $ = number of cups of tea
We want to know
who uses sugar at a faster rate — that is, who makes
more cups per pound of sugar.
This is a
rate of cups per pound of sugar — so we compare the
slope of each relationship.
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Step 1: Find Erin’s rate from the graph
From Erin’s graph:
Points on the line:
- (2, 6)
- (4, 12)
- (6, 18)
- (8, 24)
- (10, 30)
So, for every 2 pounds of sugar → 6 cups
→ Rate = $ \frac{6}{2} = 3 $ cups per pound
Or check another: $ \frac{12}{4} = 3 $, $ \frac{30}{10} = 3 $
✔ Erin’s rate = 3 cups per pound of sugar
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Step 2: Find Lucia’s rate from the equation
Given: $ y = 10x $
This means for every 1 pound of sugar ($ x = 1 $), she makes $ y = 10 $ cups.
So, Lucia’s rate =
10 cups per pound of sugar
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Compare rates:
- Erin: 3 cups per pound
- Lucia: 10 cups per pound
Since
Lucia makes more cups per pound of sugar, she uses sugar at a
faster rate (i.e., more efficiently or more intensely).
> Note: "Uses sugar at a faster rate" here means
how many cups are made per unit of sugar — so higher value = faster rate of usage in terms of output per input.
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✔ Answer to Problem 2:
Lucia uses sugar at a faster rate.
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✔ Final Answers:
1.
Leila eats more chips in 3 hours.
2.
Lucia uses sugar at a faster rate.
Parent Tip: Review the logic above to help your child master the concept of graphing proportional relationships worksheet.