A stamp collection that has an appraised value of $600 consists of twice as many foreign stamps as domestic stamps. If there is a total of 1,200 stamps in the collection, what is the total appraised value of all of the foreign stamps in the collection?There are 1200 stamps with an appraised value of $600. So, the average value of a stamp is 50 cents.
Since we are told that there are twice as many foreign as domestic stamps in the 1200, we can find the total appraised value of the foreign stamps by finding either that value or the average value of a foreign stamp, which we could then multiply by 800 to find the total appraised value.
(1) The average (arithmetic mean) appraised value of the foreign stamps in the collection is $0.06 greater than the average appraised value of the domestic stamps.We know from the passage that the ratio of foreign stamps to domestic stamps is 2:1. So, there are 800 foreign stamps and 400 domestic stamps.
We also know that the average price is 50 cents.
So, using this statement, we can say the following:
Let the average value of a foreign stamp be x.
\(\frac{800x + 400(x - 6)}{1200} = 50\)
We could solve that to find the average foreign stamp value and then multiply by 800 to find the total appraised value of foreign stamps.
Sufficient.
(2) The sum of the average (arithmetic mean) appraised values of the foreign stamps and the domestic stamps from the collection is $0.98.The average value of one stamp is 50 cents.
Let the average value of a foreign stamp be x.
Using this statement and the weighted average formula, we get the following:
\(\frac{800x + 400(98 - x)}{1200} = 50\)
We could solve that to find the average foreign stamp value and then multiply by 800 to find the total appraised value of foreign stamps.
Sufficient.
Correct answer: D