Solution:
Solution
There are $$26$$ red cards and $$26$$ black cards
i.e., total number of cards $$= 52$$
$$P$$ (both cards of different colours) is
$$P(B) P(R) + P(R) P(B)$$
$$= \dfrac {26}{52} \times \dfrac {26}{51} + \dfrac {26}{52} \times \dfrac {26}{51} = 2\left (\dfrac {26}{52}\times \dfrac {26}{51} \right ) = \dfrac {26}{51}$$.Hence, option C is correct.
