Question

Find all the values of k so that (-3,4),(-8,5) , and (-5,k) are the vertices of a right triangle.?

Answer 1

X denotes no. Of white balls drawn

Therefore 2 balls are drawn

X takes the values 0,1,2.

P(X)=7c2/10c2=7/15

E(X)=summation of X p(X)

=0+1(7/15)+2(7/15)

=7/5