4800 persons run a marathon, 1200 reach the finish line. What is the percent of people reach the finish line at the marathon?

25%

Step-by-step explanation: So first make the number of people who ran the marathon and the number of people who finished the marathon into a ratio

1200:4800

then make that into a fraction, 1200/4800

then make the percent of people who reached the marathon into a fraction, using 100 as the denominator and a variable as the numerator.

for example. p/100 (p, represents the percent)

then cross multiply.

1200x100=1200000

Last divide 1200000 by 4800 to get 25%.

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:

go and ask your mom to you