We can solve this with lots of calculations and conversions of laps to miles, etc., or we can look at what the question is really asking. We want to know how far Jake swims in the time it takes Fred to swim two miles. Instead of converting Fred's miles to laps and comparing to Jake's laps, let's just look at how fast the two brothers swim in relation to one another. Fred swims twice as fast as Jake, so in the same amount of time, he will swim twice as far as Jake. Therefore if Fred swims 2 miles, Jake swims 1 mile in the same amount of time.

60 minutes in an hour, 240 minutes in four hours. If 4 liters are poured every 3 minutes, then 4 liters are poured 80 times. That comes out to 320 liters. The tank holds 2,000 liters, so  of the tank is full.

The area of a rectangle is the length , multiplied by the width . Here the area of the lawn in meters squared is:

We found that Laura is mowing 175,000 meters squared at a rate of 20,000 meters squared per hour. 

Plugging in 20,000 for the rate, and 175,000 for the total area gives:

Multiply both sides by the total number of hours:

Now, divide both sides by 20,000: 

First add up all of the rates to get the total rate of water flowing into the pool at one time. 

Then to determine the time it takes to fill the pool divide the total volume of the pool by this rate. 

This answer of 25 hours. 

This is a rate question, so first we should rewrite the "times" given to us as rates.

Joaquin's rate :

River's rate:

Now we add their rates together, to find the rate when they work together:

Using the equiation for distance, d = rate * time we can rearrange it to see that to find time we need to do t = distance/rate

in this case, the distance is "3 pools" and the rate is "(j+r)/jr pools per minute".  So we reach our answer:

We need to convert d  miles into hours. We do so by multiplying d miles by the conversion ratio of miles to hours given in the problem, (h  hours / m  miles), as follows:

d  miles * (h  hours / m  miles) = (dh )/m  hours.

From this conversion of miles into hours, we see that the number of hours it takes Kara to drive a distance of d  miles is (dh )/m.

After watching 12 minutes of the show 18 remain. 18 is 60% of the total 30 minutes. As a fraction it can be expressed as 3/5. 

Marty's total driving time was 3 + 1 + 2 = 6 hours. He drove 40 mi/hr for 3 hours, or 3/6 = 1/2 of the time. He drove 60 mi/hr for 1 hour, or 1/6 of the drive. Lastly, he drove 70 mi/hr for 2 hours, or 2/6 = 1/3 of the drive.

To find the average speed, we need to multiply the speeds with their corresponding weights and add them up.

Average = 1/2 * 40 + 1/6 * 60 + 1/3 * 70 = 53.33... ≈ 53 mi/hr