Solutions - 5120-04

(a)

$$\begin{array}{c}P[X=5]+P[X=6]\gg \gg 0.15+0.05\gg \gg 0.20\end{array}$$

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(b)

$$\begin{array}{c}E[X]\gg \gg 0(0.10)+1(0.20)+2(0.20)+3(0.15)+4(0.15)+5(0.15)+6(0.05)\\ \\ \gg \gg 2.7\end{array}$$