A ratio is used to describe how two or more quantities are related.
For example, we might say that a fruit drink calls for sugar crystals to be mixed with water in a ratio of 2:6. This means that for every 2 scoops sugar crystals, there will need to be 6 ounces of water. If there were 200 scoops of sugar crystals, there would need to be 600 ounces of water.
This is how I'd set it up:
405/20 = 243/x
this means the mpg (miles / gallons) for 1 situation is the same as the mpg for the other situation (because the rate is the same)
then just cross multiply and solve:
405x=243*20 or 405x=4860 or x = 12
he would need 12 gallons of gas for 243 miles
The area of the circle is 3.14 square millimeters
<h3>Calculating Area</h3>
From the question, we are to the area of the circle
The area of a circle can be determined by using the formula,
A = πr²
Where A is the area of the circle
and r is the radius of the circle
From the given information,
r = 1 mm
and π = 3.14
Putting the parameters into the equation, we get
A = 3.14 × 1²
A = 3.14 × 1
A = 3.14 mm²
Hence, the area of the circle is 3.14 square millimeters
Learn more on Calculating Area here: brainly.com/question/15673093
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