The correct option is
B 143E(X) is nothing but mean of X
→ first sic natural numbers are
1,2,3,4,5,6
→We can select two positive no.s in
6×5=30 ways
→2 numbers are selected at random among which X denotes the larger of the two no.s
→But as X is largest among the two ,
it can be 2,3,4,5 or 6
∴P(X=2)=P (larger no. is 2) (1,2),(2,1)
=230
→P(X=3)=P (Larger no. is 3)
={(1,3),(3,1),(2,3),(3,2)}
=430
→P(X=4)=P (larger no. is 4)
={(1,4),(4,1),(2,4),(4,2),(3,4),(4,3)}
=630
→P(X=5)=P (Larger no. is 5)
={(1,5),(5,1),(2,5),(5,2),(3,5),(5,3),(4,5),(5,4)}
=830
→P(X=6)=P (Larger no. is 6)
={(1,6),(6,1),(2,6),(6,2),(3,6),(6,3),(4,6),(6,4),(5,6),(6,50)}
=1030
∴E(X)= mean =∑P(Xi).Xi
=2(230)+3(430)+4(630)+5(830)+6(1030)
=14030=143