A car dealership has 40 cars on the lot, 20% of which are silver. If the dealership receives a new shipment of 80 cars, 50% of which are not silver, what percentage of total number of cars are silver?	Choose the correct option
A) 30 %
B) 35 %
C) 40 %
D) 45 %
E) 50 %

Rationale: "the number of silver cars is 0.2 * 40 + 0.5 * 80 = 48 the percentage of cars which are silver is 48 / 120 = 40 % the answer is c ."
Answer: C