Ramit88 wrote:A certain jar contains only b black marbles, w white marble, and r red marble. If one marble is to be chosen at random from the jar, is the probability that the marble chosen will be red greater than the probability that the marble chosen will be white?
(1) r/(b + w) > w/(b + r)
(2) b-w > r
Probability that the marble chosen will be red P(r) = r/(b + r + w)
Probability that the marble chosen will be white P(w) = w/(b + r + w)
Statement 1: r/(b + w) > w/(b + r)
Implies, (b + w)/r < (b + r)/w
Adding 1 to each side, 1 + (b + w)/r < 1 + (b + r)/w
=> (r + b + w)/r < (w + b + r)/w
=> r/(b + r + w) > w/(b + r + w)
=> P(r) > P(w)
Sufficient
Statement 2: (b - w) > r
Doesn't imply anything relevant.
Not Sufficient
The correct answer is A.
