Number - Plants / Hills per Acre

Two related problems:

A) A farmer has a crop to plant in an acre. He plans to use 3' 6" rows, 3 plants per hill, hills 3' 6" apart. Determine number of plants.

B) The same farmer plans to have a number of hills in 3' 6" rows, 3' 6" apart in an acre. Determine number of hills.


An acre contains:

43560 square feet

208.71 feet x 208.71 feet

4840 square yards


How do I proceed ?

Non - homework question.