There rotten apples are mixed accidently with seven good apples and four apples are drawn one by one without replacement. Let the random variable X denote the number of rotten apples. If μ � and σ2 represent mean and variance of X, respectively, then 10 (μ2+σ2) is equal to
(a) 20
(b) 250
(c) 25
(d) 30