Original:
30% of 40 cars are silver --> 12 cars are silver.

New shipment:
40% are NOT silver --> 60% are silver
60% of 80 cars --> 48 silver cars

Total:
silver: 12 + 48 = 60
all: 40 + 80 = 120
60/120 = 50% of all cars are silver

The answer is E.

swerve wrote:A car dealership has 40 cars on the lot, 30% of which are silver. If the dealership receives a new shipment of 80 cars, 40% of which are not silver, what percentage of the total number of cars are silver?

A. 35%
B. 37.5%
C. 45%
D. 47.5%
E. 50%

The OA is E.

Source: Manhattan Prep

Before the shipment, the car dealership has 0.3 x 40 = 12 silver cars. The shipment has 0.6 x 80 = 48 silver cars. Thus, after the shipment, the dealership has 12 + 48 = 60 silver cars out of a total of 40 + 80 = 120 cars. We see that the percentage of cars that are silver is 60/120 = 1/2 = 50%.

Answer: E