Question

It takes Myrna one hour to decorate 3 and 1/4 dozen cookies.How many dozen cookies can Myrna decorate in 2 and 1/3 hours?​

Answer 1

Hello!

The answer is:

Myrna can decorate

`7(7)/(12)` dozens of cookies in
`2(1)/(3)` hours.

Why?

To solve this problem, we need to remember how to multiply mixed numbers, we can do it by the following way:

- Covert the mixed numbers to improper fractions

- Multiply the improper fractions

- Convert the result to mixed number again.

Also, we need to pay attetion to the given rate about Myrna's work.

So,

`Rate=(3(1)/(4)dozen)/(hour)`

Then, to calculate how many dozen of cookies can Myrna decorate in 2 and 1/3 hours, we need to write the following equation:

`Work=Rate*Time`

We already know the Myrna's rate, so substituting it into the equation to know how many dozen of cookies she can decorate in 2 and 1/3 hours, we have:

`Work=(3(1)/(4))(dozen)/(hour) *(2(1)/(3))hour`

Now, multiplying the mixed numbers we have:

- First, converting to improper fractions:

`(3(1)/(4))=3+(1)/(4)=(12+1)/(4)=(13)/(4)\\\\(2(1)/(3))=2+(1)/(3)=(6+1)/(3)=(7)/(3)`

- Second, multiplying the fractions:

`((13)/(4))*((7)/(3))=(13*7)/(7*3)=(91)/(12)`

- Converting back to mixed number:

`(91)/(12)=7.58=7(7)/(12)`

So, the answer is:

Myrna can decorate

`7(7)/(12)` dozens of cookies in
`2(1)/(3)` hours.

Have a nice day!