Question 866135
{{{P(1)=4/(4+2+3+1)=4/10=2/5}}}
{{{P(5)=2/10=1/5}}}
{{{P(10)=3/10}}}
{{{P(20)=1/10}}}
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{{{E=(4/10)(1)+(2/10)(5)+(3/10)(10)+(1/10)(20)}}}
{{{E=0.4+1+3+2}}}
{{{E=6.40}}}