The question is incomplete! Complete question along with answer and step by step explanation is provided below.
Question:
1. Solve this problem by working backwards. Check your answer by working forwards. Leona set up a fruit stand to soil some of her crop of oranges. The first person to come by bought 1/3 of her oranges. The second person bought 4. The third person then bought 1/4 of the remaining oranges. Leona took the last 15 oranges home and made orange juice. How many oranges did Leona have when she set up the fruit stand?
Answer:
Number of oranges = 36
Explanation:
Working from backwards:
Let x is the number of unknown oranges
we know that Leona took last 15 oranges home which which was left when the third person bought 1/4 of her oranges so
x - 1/4x = 3/4x
So the remaining oranges were
3/4x = 15
x = 4*15/3
x = 20
So that means Leona had 20 oranges before the third person bought the oranges.
Then 2nd person bough 4 of her oranges
x = 20 + 4
x = 24
So that means Leona had 24 oranges before the second person bought the oranges.
Then 1st person bought 1/3 of her oranges
x - 1/3x = 2/3x
So the remaining oranges were
2/3x = 24
x = 3*24/2
x = 36
That means Leona had 36 oranges before the first person bought the oranges which is basically the time when she set up the fruit stand.
Now lets verify our answer by working forward:
x = 36
1st person bought 1/3 of her oranges.
36*1/3 = 12
x = 36 - 12
x = 24
2nd person bought 4 of her oranges.
x = 24 - 4
x = 20
3rd person bought 1/4 of her oranges.
20*1/4 = 5
x = 20 - 5
x = 15
Therefore, Leona took these remaining 15 oranges to home and our answer is correct.