Puala and kelly are comparing their ruining times. puala completed a 10-mile run in 65 minuets. kelly completed 10-kilometre run in 40 minuets. given that 8 kilometre are equal to 5 miles, whch girl has the greatest average speed?

If 8 km equals 5 miles then that means Paula ran 16 kilometers in 65 minutes.

And we already know that kelly  ran 10 kilometers in 40 minutes

do 40/10 which is 4 and 65/16 which is 4.062

Therefore Paula had the greatest average speed

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so:

6mm^3 or .6cm^3

      216

      /   \

  36     6

  /   \     /

6     6   6

factor trees are nice.