Question

Natalie walked 3 5 mile in 1 2 hour. How fast did she walk, in miles per hour?

Answer 1

420 miles per hour......................

Answer 2

She walked 1.2 (6/5) miles per hour.

Explanation:

The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three. Remember that proportionality is a constant relationship or ratio between different magnitudes.

If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other, the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:

a ⇒ b

c ⇒ x

So,

`x=(c*b)/(a)`

In this case the rule of three is applied as follows: If Natalie travels 3/5 miles in 1/2 hour, how many miles does she travel in 1 hour?

So,

`miles=(1 hour*3/5miles)/(1/2hour)`

`miles=((3)/(5) )/((1)/(2) )`

To divide these fractions you must reverse the SECOND FRACTION, that is, change the denominator to the numerator and change the numerator to the denominator. Then, the two fractions are multiplied. Then:

`miles=((3)/(5) )/((1)/(2) ) =(3)/(5) *(2)/(1) =(3*2)/(5*1) =(6)/(5)`

Then, Natalie traveled 6/5 miles per hour Also considering that 6/5 is 1.2, it is also said that Natalie's speed is 1.2 miles per hour.