Bunuel wrote:
At a certain fruit stand, the price of each apple is 40 cents and the price of each orange is 60 cents. Mary selects a total of 10 apples and oranges from the fruit stand, and the average (arithmetic mean) price of the 10 pieces of fruit is 56 cents. How many oranges must Mary put back so that the average price of the pieces of fruit that she keeps is 52 cents?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5
Kudos for a correct solution.
here price of apple = 40 cents and price of orange = 60 cents
average price = 56 cents
so, the apples and oranges are in ratio
apple : orange = 60 - 56 : 56 - 40
=> apple : orange = 4 : 16
=> apple : orange = 1 : 4
total no =10, therefore apples = 2 nos. and oranges = 8 nos.
now we have to make average price = 52 centsso, the apples and oranges will be in ratio
apple : orange = 60 - 52 : 52 - 40
=> apple : orange = 8 : 12
=> apple : orange = 2 : 3
now we have apples = 2 nos. from above, therefore oranges must be 3 in number
oranges to be put back = 8 - 3 = 5 nosAnswer choice Ekudos if you like the explanation
Thank you for this, this is how I started solving as well. However, I counted the oranges in second round as 6 (because (3/5)*10 =6) and so my answer was 8-6 = 2. Can you please explain why we take the oranges as 3, not 6?