Number System
A certain number successively divided by 2, 5 and 7 leaves remainders 1, 2 and 3 respectively. When the same number is divided by 70, what is the remainder?
Two balls can be drawn from 18 balls in 18C2 Ways, ie 153 ways. One white from 8 white balls can be drawn in 8C1 = 8 ways and one black ball from 10 black can be drawn in 10C1 = 10 ways.∴ n(S) = 153, n(E) = 8 x 10 = 80∴ P(E) = 80/153