If each customer at the outdoor movie last night came in a

[BTGmoderatorLU]

Source: GMAT Prep

If each customer at the outdoor movie last night came in a car, what was the number of cars in which the customers came to the outdoor movie last night?

1) The average (arithmetic mean) number of customers per car coming to the outdoor movie last night was 2.
2) Total receipts at the outdoor movie last night were $4,500 at $5 per customer.

The OA is C.

[deloitte247]

Statement 1
The average arithemetic mean number of customers per car leading to the outdoor movie last right was 2
From the arithemetic mean of $$\frac{EFX}{EF}$$
$$Average\ customer\ per\ car\ =\frac{Total\ Customer}{No\ of\ cars}$$
Average customer per car= 2 but we were not given any information on Total customers so we cant find total number of cars.
Hence statement 1 is INSUFFICIENT.

Statement 2
Total receipts at the outdoor movie last night were 4500 dollars at 5dollar per customer.

$$So\ Total\ customer\ =\frac{Total\ receipts}{receipts\ per\ customer}=\frac{4500}{5}=900customers$$
But we cannot find the total number of cars from this piece of information
Hence statement 2 is INSUFFICIENT.

combining statement 1 and 2 together
Total customers = 900
Average customer per car = 2
$$Average\ customer\ per\ car=\frac{Total\ Customers}{Total\ number\ of\ Cars}$$
Make Total number of Cars the subject formular.
$$Total\ numbers\ of\ Cars=\frac{Total\ Customers}{Average\ Customer\ per\ car}$$
$$Total\ numbers\ of\ Cars=\frac{Total\ Customers}{Average\ Customer\ per\ car}=\frac{900}{2}=450cars$$
$$Both\ statement\ combined\ together\ are\ SUFFICIENT.$$
$$answer\ is\ Option\ C$$