Answer:
200 kg
Explanation:
First hour he sold 15% (remaining is 85%)
Second hour he sold 20% of remaining (which is 85%) -- so he sold
, which is 17% (remaining 85-17=68%)
Third hour he sold 25% of remaining (which is 68%) -- so he sold
, which is 17%
In third hour he sold 34, so 17% is 34. To find total he initially had, we need to find (100%). We can setup the ratio (letting x equal his initial amount):

Initially the farm stand owner had 200 kg of apples.