A certain group of car dealerships agreed to donate x dollars to a Red

Combing both; 500 car was expected to be sold; it actually sold 560 cars;

Donated; 28000 for 560 cars
Donated per car;
28000/560 = $50

It was expecting to donate; 500*50=25000
Sufficient.

Ans: "C"

From statement 1, total expected donation is 500x, insufficient as we do not know x
From Statement 2, if initial expectation was to sell N cars then (N+60)*x = 28000, we need to find amount expected to be donated which is N*x, but we cant determine that if we do not know x, so insufficient.
Combining 1 and 2, we know N = 500,
so, (560)*x = 28000 or x =28000/560 = 50 hence expected amount = 500*50 = 25000, Sufficient
Answer C

Official Guide:

In data sufficiency problems that ask for the value of a quantity, the data given in the statements are sufficient only when it is possible to determine exactly one numerical value for the quantity.

Statement (1) gives us the expression with unknown (500x) rather than single numerical value for the quantity thus it's not sufficient.

Hope it's clear.
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A certain group of car dealerships agreed to donate x dollars to Red Cross chapter for each car sold during the 30 day period. what was the total amount that was expected to be donated?

(1) A total of 500 cars were expected to be sold
(2) 60 more cars were sold than expected, so that the total amount actually donated was 28,000$


I came with E and was wrong
My point was that the first statement doesn't tell us that the plan to sold 500 cars was established for the 30day period. Just in general to sell 500 cars
Please - what can't i grasp here - could someone tell me?

Hi,

This is how I broke it down & I think I did fall for the trap answer e.

Statement 1: expected cars to be sold = 500 Not Sufficient as donation amt nt given

Statement 2 expected cars + 60 cars) x donation per car = 28000
Not sufficient

Combined 560 x donation per car = 2800

Hence sufficient

We miss that its expected cars + 60 & not actual cars + 60

Posted from my mobile device

Guys
i understand that the question is pretty simple )
but i used to think data can be sufficient only if it gives us necessary information
I read the first statement as "500 cars will be sold in general, not during the month, within which the agreement took place".
Otherwise it should be written " A total of 500 cars were expected to be sold within the 30 day period"
Anyway, C is correct, and I must to go w it

Hi Gailiya,

I understand your point. I had a similar problem with another question. Go to think link and have a look:

all-the-clients-that-company-x-had-at-the-beginning-of-last-128023.html


Sometimes, GMAT questions expect us to assume that certain information is understood. I personally feel such GMAT questions are flawed.


Hope this helps.

Thank you, Naina!
will try to figure out such a flaws )

Missed the key words Expected & Actual...

Went with E, but C is the correct answer

Is the answer when combined 25000?

Let n be the total number of cars and X be the amount

Statement 1

Gives us n = 500, X = ?

we dont' know X not sufficient

Statement 2

(n+60) X = 28000

Not sufficient

Combined

560 X = 28000

X = 50

Nx = 500 * 50 >> 25000

Sufficient C

A certain group of car dealerships agreed to donate x dollars to a Red Cross Chapter for each car sold during a 30-day period.What was the total amount that was expected to be donated?

(1) A total of 500 cars were expected to be sold
(2) Sixty more cars were sold than expected, so that the total amount actually donated was $28,000

statement 1: we are only given how many cars were expected to be sold. We need amount donated per car to find out expected donation.
statement 2: so what if 60 more cars were sold...we don't know how many were expected to sold

1+2:-

We have the total donation amount and number of cars we can find the amount donated for each car:

28000/560= 50

expected---50*500= 25000

Ans is C.

we need both statement one and two as question is (total amount that was expected to be donated)
hence c

Is the 30-day period mentioned in the question completely irrelevant in this case? What if the amounts given would have been over a 60-day period and we don't know it - wouldn't we have had to double the amounts? I had put ''E - Neither'' because of that.

Why do we assume that each car contributes the same amount?