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## 6th grade (Illustrative Mathematics)

### Unit 3: Lesson 3

Lesson 6: Interpreting ratios# Solving unit rate problem

CCSS.Math:

Jayda takes 3 hours to deliver newspapers on her route. What is the rate per hour at which she delivers the newspapers? Created by Sal Khan and Monterey Institute for Technology and Education.

## Want to join the conversation?

- Is 2:5 the same as 5:2(1 vote)
- The order of the #s matter.

If the problem were (for example) There are 15 kids who have pets in a class. There are 33 kids in the class. What is the ratio of kids who have pets to kids who do not? The answer would be15:18. If you said18:15you would be saying the ratio of kids who do**NOT**have pets to kids who**DO**have pets.(2 votes)

- Yes tis has helped me a lot now I will die as a happy man(10 votes)
- wow that doesn't sound good ur not old yet(1 vote)

- how do i solve a unit rate problem if there are fractions in them? For example, the unit rate of 2/3 cup of sugar for every 1/2 teaspoon of vanilla(6 votes)
- Divide 2/3 and 1/2. Do the same method even if it's a fraction.(4 votes)

- I don't understand these problems...

Fill in the blank with the unit rate:

240 km in 2.5 hours =*____*km in 1 hour

Fill in the blank with the unit rate:

$15 for 4 quarts = $ for 1 quart

There are 25 computers in a math lab. There are 6 activity booklets for every 2 computers in the math lab. How many activity booklets are in the math lab?

There are activity booklets in the math lab.

You earn $102 for doing 12 hours of yard work. Your friend earns $120 working at a store for 15 hours.

How much do you earn for every hour of yard work? $ per hour

How much does your friend earn each hour at the store? $ per hour

What would YOU earn for 15 hours worth of yard work (at your hourly rate)? $ for 15 hours of work(8 votes)- what helps me is writing the numbers out in a fraction. the first one, how many kms are in one hour if 240 are in 2.5, or 2 and a half, or 2 hrs and thirty minutes. you divide both 2.5 and 240 by 2.5 to get the original ratio.(0 votes)

- the ratios are the same with 5 apples and 6 banana too so it is it is still 5.6 or 6.5(7 votes)
- What is the difference between unit rates and price?(2 votes)
- unit rates always have a denominator of one. When prices are expressed as a quantity of one, they are called unit prices. A price is how much you actually pay. The unit price is just per one thing. :)(9 votes)

- What if the numerator is not divisible by the denominator? For example, 42 cupcakes can be made every 30 minutes. How many cupcakes can be made in 1 minute?(3 votes)
- It depends on the question.

Example:

7 leaves fall from the tree every 3 minutes. ABOUT how many leaves will fall from the tree in 1 minute?

Answer:

You would divide 7 by 3, which equals 2.3333333.... Since the question asks ABOUT how many, you can round it to 2. since 2 times 1 equals 2,then that is your approximate answer.

Hope this helps!(6 votes)

- You basically divide both by a divisor then simplify.

-Tell if it helps.(5 votes) - what is unite rate though?(4 votes)
- Unit rates are used to find out how much things happen at a time or ex. rooms per hotel.(2 votes)

- does the tutorial dude have a name?(2 votes)
- His name is Salman (Sal) Khan. He's actually the founder of Khan Academy but has posted most of the tutorial videos. He's posted over a thousand, actually!(5 votes)

## Video transcript

Jayda takes 3 hours to deliver
189 newspapers on her paper route. What is the rate per
hour at which she delivers the newspaper? So this first sentence tells us
that she delivers, or she takes, 3 hours to deliver
189 newspapers. So you have 3 hours for
every 189 newspapers. That's what the first
sentence told us. But we want to figure out the
rate per hour, or the newspapers per hour, so we can
really just flip this rate right here. So if we were to just flip it,
we would have 189 newspapers for every 3 hours, which is
really the same information. We're just flipping what's in
the numerator and what's in the denominator. Now we want to write it in as
simple as possible form, and let's see if this top number
is divisible by 3. 1 plus 8 is 9, plus 9 is 18. So that is divisible by 3. So let's divide this numerator
and this denominator by 3 to simplify things. So if you divide 189 by 3. Let's do it over on the
side right here. 3 goes into 189. 3 goes and 18 six times. 6 times 3 is 18. Subtract. Bring down the 9. 18 minus 18 was nothing. 3 goes into 9 exactly
three times. 3 times 3 is 9, no remainder. So if you divide 189 by 3, you
get 63, and if you divide 3 by 3, you're going to get 1. You have to divide both the
numerator and the denominator by the same number. So now we have 63 newspapers
for every 1 hour. Or we could write this as 63
over 1 newspapers per hour. Or we could write this as 63,
because 63 over 1 is the same thing as 63 newspapers
per hour.