if 2 chords of ellipse have the same
distance from the centre of ellipse
and the eccentric angle of the end points of the chords
are respectivly α β γ δ then prove that
tan (α/2)×tan (β/2)×tan (γ/2)×tan (δ/2)=1
(1) There are 20 boys and 10 girls in a
class.If a committee of 6 is to be
chosen at random having atleast
2 boys and 2 girls,find the
probability that
(i) there ara 3 boys in the
committee
(ii) there are 4 boys in the
committee