Answer: 0.2
Step-by-step explanation:
Number of ways to select r things out of n things = [tex]^nC_r=\dfrac{n!}{r!(n-r)!}[/tex]
Then , Total number of ways to select 2 out of 5 chores = [tex]^5C_2=\dfrac{5!}{2!3!}=\dfrac{5\times4\times3!}{2\times3!}=10[/tex]
Number of ways to selecting first 2 on list = 2 (either he choose top on the list first then second , or second person first then topper)
Now , the probability he will choose the first 2 on list = [tex]\dfrac{2}{^5C_2}=\dfrac{2}{10}=0.2[/tex]
Hence, the probability he will choose the first 2 on list is 0.2.
