Explanation:
the other answer can be a bit confusing.
and the last sentence there is wrong. it should be 2 parts plus 5 parts is 7 parts.
anyway, in questions like this you need to first clarify : how many parts are being used as the whole.
think of it like a cake or a pizza. one friend will eat 2 slices, another will eat 3 slices, and you want only one. then into how many slices do you have to cut the pizza, if there should be no pizza left ?
so, in our case here, the drinks get 2 "slices" of the whole pizza of $35. and food gets 5 "slices". and together they have now the whole pizza.
so the whole pizza was cut into 2+5 = 7 slices.
now we need to spread the whole $35 "pizza" evenly on its 7 slices (or parts).
remember : we use division for that.
35/7 = $5
so, one slice (or part) of the whole $35 is $5.
since drinks get 2 slices (or parts), this is then 5+5 or 5×2 = $10
and food gets 5 slices (or parts). this is then 5+5+5+5+5 or 5×5 = $25
and to verify : $10 + $25 = $35. so, yes, we did not make any mistake. the sum is indeed the total of $35.