Aperson who weighs 240 pounds burns 180 calories per mile of running. if a person burns thirty-six calories by running one mile, how much does the person weigh?

Well I figure you would use a ratio. we are given one when comparing 240 lbs to 180 calories for each mile:
240lbs/180calories = 1 mile

we.are.given another when saying a person. burns 36 calories in 1 mile. we don't know weight so we will say x lbs:
x/36calories = 1 mile

since they both equal 1 mile we know they are equal:
240/180 = 1 = x /36

we can get rid of the 1 in between and say:
240/180 = x/36

let's reduce first fraction
8/6 = x/36

cross multiply:
8*36 = 6x

divide both sides by 6
8*6 = x

x = 48