Answer :
First we calculate classroom surface:
35*40=1400 square ft
we know that for every 100 square ft 2 or 3 pots can be put
so 1400/100=14
14*2=28
14*3=42
we need 28 or 42 pots
35*40=1400 square ft
we know that for every 100 square ft 2 or 3 pots can be put
so 1400/100=14
14*2=28
14*3=42
we need 28 or 42 pots