After a genetics experiment on 56 pea plants, the number of plants having certain characteristics was tallied, with the results given to the right. Answer parts (a) through (c). 19 were tall; 31 had green peas; 35 had smooth peas; (a) Find the number of plants that were tall and had smooth peas. 9 were tall and had green peas; 20 had green peas and smooth peas; 7 had all three characteristics; plants 5 had none of the characteristics.