A box contains 15 green and 10 yellow balls. If 10 balls are randomly drawn, one-by-one, with replacement, then the variance of the number of green balls drawn is: (1) $\dfrac{12}{5}$ (2) $6$ (3) $4$ (4) $\dfrac{6}{25}$
A box contains 15 green and 10 yellow balls. If 10 balls are randomly drawn, one-by-one, with replacement, then the variance of the number of green balls drawn is:\\
(1) $\dfrac{12}{5}$\\
(2) $6$\\
(3) $4$\\
(4) $\dfrac{6}{25}$