Problem: the total cost of 100 paper plates and 200 paper cups is $ 4.50 at the same rates what is the total cost of 20 of the plates and 40 of the cups ?
Rationale: "u dont need to go through all this what u have with u is 100 p + 200 c = $ 4.50 just divide the equation by 5 and you will get what u are looking for 20 p + 40 c = $ 0.90 therefore oa is a"
annotated_formula: multiply(divide(20, 100), 4.50)