Chris uses 9 cups of sugar to make 24 cookies. if he keeps the recipe the same, how many cups of sugar will he need to make 72 cookies?

so since the ratio is 9:24, and 72 can be divided by 24, and its three, so we multiply 9 too to get 27:72, and if we divide them by 3, were back to 9:24 so we know it works

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.