The contents of a certain box consist of 72 apples and 30 oranges. How many oranges must be added to the box so that exactly 30% of the pieces of fruit in the box will be apples?
Choose the most appropriate option.
A) 68 B) 78 C) 88 D) 138 E) 108
apple = (apple + orange + x)*0.3   72 = (30 + 72 + x)*0.3   x = 138   Answer: 138
<result>D</result>
The contents of a certain box consist of 72 apples and 30 oranges. How many oranges must be added to the box so that exactly 30% of the pieces of fruit in the box will be apples?