yes
No.
Divide the pear trees by 4 then multiply the result by 3 to get the answer.
ya, some types
It depends on the type of apple tree, some are self pollinating and some need other trees pollen in order to pollinate.
No It's physicly impossible
No.
The most common are fir trees, oaks, birches and fruit trees (apple, pear, cherry).
Parker or Patten will pollinate a Summer Crisp.
The apple is commercially the most important of the world's deciduous fruit trees, and is follwed by the pear. In the United States, however, the pear ranks third, after the apple and peach.
Not necessarily. If you have other plants in your garden (Flowers, shrubs, etc.) you will not need two apple trees. If you have no other plants in your garden, then yes, you will need two apple trees to pollinate.
Apple farmers need bees to pollinate their apple trees. Where bees have been eradicated by pesticides, more bees, or hand pollination, are necessary for the trees to bear fruit.