The equation for the probability that student sings or rap in the shower 3-4 times a week is,
[tex]P\text{ (sing or rap)=P(sings) + P(rap) - P(Sings and rap)}[/tex]
Substitute the values in the equation to determine the probability hat student sings or rap in the shower 3-4 times a week.
[tex]\begin{gathered} P\text{ (sings or rap)=0}.4+0.5-0.2 \\ =0.9-0.2 \\ =0.7 \end{gathered}[/tex]
So answer is 0.7.
