Note that the number of pears and apples are equal at the end.

Also, the initial question seems wrong, so you may wish to change the word "oranges" with "pears".

We are left with 4/5 of the pears.

Let the initial number of pears be 5 units (this will be drawn as 5 units in the original model).

The final number of pears would be 4 units, so the final number of apples would also be 4 units.

Initially, there were 5 units pears and (4 units + 111) apples. This would total up to 300 fruits, so

5 units + 4 units + 111 fruits = 300 fruits
9 units + 111 fruits = 300 fruits
9 units = 300 fruits - 111 fruits
9 units = 189 fruits
1 unit = 189/9 fruits (/ is used as a divide sign)
1 unit = 21 fruits

There were 5 units of pears at first.

5 units = 21 fruits x 5
5 units = 105 fruits

So, there were 105 pears at first.