At a certain food stand, the price of each apple is 40¢ and the price of each orange is 60¢. Mary selects a total of 10 apples and oranges from the food stand, and the average (arithmetic mean) price of the 10 pieces of fruit is 54¢. How many oranges must Mary put back so that the average price of the pieces of fruit that she keeps is 45¢?	Choose the correct choice:
A) 2	B) 3	C) 4	D) 5	E) 6
If the average price is 54, then Mary has 7 oranges and 3 apples (a ratio of 7:3).   For the average price to be 45, the ratio should be 1:3.   Mary must put back 6 oranges.   The answer is 6.
<result>E</result>
At a certain food stand, the price of each apple is 40¢ and the price of each orange is 60¢. Mary selects a total of 10 apples and oranges from the food stand, and the average (arithmetic mean) price of the 10 pieces of fruit is 54¢. How many oranges must Mary put back so that the average price of the pieces of fruit that she keeps is 45¢?