Question

Dorell attempted 40 shots he made 18 he says he made 40% of the shots is he right

Answer 1

18/40 simplified to 9/20.
9/20 is .45, or 45%.
While Dorell did not make exactly 40% of the shots he made, which I assume is what the question is asking, he did make at least 40%. 45% is at least 40%, after all.
So, he is not right if I understand the question to ask if he made exactly 40% of his shots.