Answer:
9
Step-by-step explanation:
Given that :
Total number of Tshirts = 30
% of blue T shirts = 20%
% of black T shirts = 50%
Number of Blue = 0.2 * 30 = 6
Number of black = 0.5 * 30 = 15
Number of Tshirts that are neither black nor blue :
Total - ( number of blue + number of black)
30 - (15 + 6)
30 - 21 = 9
9 Tshirts
