Divide the number of revolutions by the number of minutes to get revolutions per minute:

\(\displaystyle 330\div 15 = 22\),

making \(\displaystyle 22\) revolutions per minute the correct choice.

First, find out how long it takes the factory to produce \(\displaystyle 1\) tent.

\(\displaystyle \frac{15}{300}=0.05\)

Since it takes the factory \(\displaystyle 0.05\) minutes to make \(\displaystyle 1\) tent, multiply this number by \(\displaystyle 9000\) to find how long it takes to make \(\displaystyle 9000\) tents.

\(\displaystyle 0.05\times9000=450\)

It will take the factory \(\displaystyle 450\) minutes to make \(\displaystyle 9000\) tents.

First, find how many cans of soda Billy can drink in 1 day.

\(\displaystyle \frac{12}{4}=3\)

Since, he can drink \(\displaystyle 3\) cans in \(\displaystyle 1\) day, then the following equation will tell us how many cans he drinks in \(\displaystyle 2\) days.

\(\displaystyle 3\times2=6\)

First, find the cost per marker.

\(\displaystyle 45\div15=3\)

Now, multiply this cost per marker by \(\displaystyle 25\), the number of markers we want.

\(\displaystyle 25\times3=75\)

Set up the following proportion:

\(\displaystyle \frac{2}{0.5}=\frac{200}{x}\),

where \(\displaystyle x\) is the number of hours it'll take to empty \(\displaystyle 200\) gallons.

Now solve for \(\displaystyle x\).

\(\displaystyle 2x=100\)

\(\displaystyle x=50\)

First, figure out how long it takes Julie to read 1 page.

\(\displaystyle 2\div5=0.4\)

It takes Julie \(\displaystyle 0.4\) minutes to read one page. Now, multiply this by the number of pages she needs to read to find out how long it will take her.

\(\displaystyle 0.4\times120=48\)

It will take Julie \(\displaystyle 48\) minutes to read \(\displaystyle 120\) pages.

Divide the time it take Dennis to paint \(\displaystyle 8\) walls by the number of walls he painted to find how long it will take him to paint one wall.

\(\displaystyle 120\div8=15\)

It will take Dennis \(\displaystyle 15\) minutes to paint one wall.

First, find out how much money it costs to play for one minute.

\(\displaystyle 1.25\div3=0.41667\)

Now, multiply this amount by the number of minutes in an hour to find how much it will cost for the player to play for one hour.

\(\displaystyle 0.41667\times60=25\)

It will cost her \(\displaystyle \$25\) to play for one hour.

First, convert the minutes to hours.

\(\displaystyle 45\div60=0.75\)

Since \(\displaystyle 45\) minutes is \(\displaystyle 0.75\) hours, multiply this by the doctor's hourly rate to find how much it will cost to hire this doctor for \(\displaystyle 45\) minutes.

\(\displaystyle 500\times0.75=375\)

Use the dentist's rate to find how much the first three hours of the appointment will cost.

\(\displaystyle 50\times 3=150\)

Next, use the dentist's second rate to find out how much the last five hours of the appointment will cost.

\(\displaystyle 25\times5=125\)

Now, add these values together to get the cost of the entire appointment.

\(\displaystyle 150+125=275\)