Question

Fiona and Camilla took a load of peaches to the farmer’s market. During the first hour, they sold ½ of the peaches plus ½ of a peach. In the second hour, they sold 1/3 of the remaining peaches plus 1/3 of a peach. In the third hour, they sold ¼ of what was left plus ¾ of a peach. During the final hour, they sold 1/5 of the peaches that were left plus 1/5 of a peach. Fiona and Camilla went home with 19 whole peaches. How many peaches did they take to the market?

Answer 1

They took 101 peaches to market.

Check:

In the 1st hour, they sold (101/2 + 1/2) = 102/2 = 51.  They had 50 left.

In the 2nd hour, they sold (50/3 + 1/3)=51/3=17.  They had (50-17)=33 left.

In the 3rd hour, they sold (33/4 + 3/4) = 36/4 = 9.  They had (33-9) = 24 left.

In the final hour, they sold (24/5 + 1/5) = 25/5 = 5.  They had (24-5) = 19 left.  yay!

Fiona and Camilla took their 19 remaining peaches and went home.  Sharing with
their parents and their brother Rowlf, each person had 3.8 peaches for dinner.
There was a lot of activity in the bathroom overnight.

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The key to solving this one is to work it backwards.

-- They had 19 peaches left at the end of the day.

-- During the final hour, the 1/5 of a peach that they sold left them with 19,
so they had 19-1/5 before they sold the 1/5 of a peach.
The 19-1/5 was 4/5 of what they had at the beginning of the final hour.
So, at the beginning of the final hour, they had (5/4)x(19.2) = 24 .

-- During the 3rd hour, the 3/4 of a peach that they sold left them with 24,
so they had 24-3/4 before they sold the 3/4 of a peach.
The 24-3/4 was 3/4 of what they had at the beginning of that hour.
So, at the beginning of the 3rd hour, they had (4/3)x(24.75) = 33 .

Do the same for the 2nd hour.

Then do the same for the 1st hour.

And you'll work your way back up to 101 peaches.