Each car is sold at either $20000 or $30000
Total car sold = 50

Question=> What is the total profit of the dealer?

Statement 1: 20 cars were sold for $20000.
There is no information about the cost price. Hence, statement 1 is NOT SUFFICIENT

Statement 2: 30 cars were marked up at 30% .i.e remaining 20 were marked up at 20% of cost price but the value of cost price is unknown, hence, Statement 2 is NOT SUFFICIENT

So, combining the two statement together.
20 cars sold at $20000 and 30 cars were marked up at 30% or remaining 20 were marked up at 20% of the cost price.
Let
$$CP_x=cost\ price\ of\ 20\ cars$$
$$CP_y=\cos t\ price\ of\ 30\ cars$$
Total selling price = 20 * 20000 = $400,000
$$1.2CP_x=400,000$$
$$CP_x=\frac{400,000}{1.2}=$333,333$$

Similarly for 30 cars,
Total selling price = 30 * 30,000 = $900,000
$$1.3CP_y=900,000$$
$$CP_y=\frac{900,000}{1.3}=$692,307$$

For 20 cars profit = selling price - cost price
=400,000 - 333,333 =$366,667

For 30 cars profit = 900,000 - 692,307 = $207,693

The total profit of dealer = 366,667 + 207,693 = $574,360
Hence, Both statement are SUFFICIENT.... Thus, the answer is Option C

AAPL wrote:e-GMAT

An auto dealer sells each car at either $20,000 or $30,000. Some cars are marked up at 20% of the cost price and the remaining are marked up at 30% of the cost price. If the dealer sells 50 cars in total, what is the total profit of the dealer?

1) 20 cars were sold for $20,000.
2) 30 cars were marked up at 30%.

Statements combined:
Case 1:
30 $30,000 cars are marked up 30%'
20 $20,000 cars are marked up 20%

Case 2:
10 $30,000 cars are marked up 30%
20 $20,000 cars are marked up 30%
20 $30,000 cars are marked up 20%

In Case 1, the more expensive $30,000 cars are all sold at the higher profit margin -- 30% -- with the result that the total profit in Case 1 will be greater than the total profit in Case 2.
Since the total profit can be different values, the two statements combined are INSUFFICIENT.

The correct answer is E.