A box contains three colored marbles, such that the number of blue, yellow and grey marbles is 8, 7 and 5 respectively. Find the probability of picking two marbles, one being blue marble and the other being grey marble.

Question: A box contains three colored marbles, such that the number of blue, yellow and grey marbles is 8, 7 and 5 respectively. Find the probability of picking two marbles, one being blue marble and the other being grey marble.

Solution:
From the given data,
Number of blue marbles = 8
Number of yellow marbles = 7
Number of grey marbles = 5

∴ Probability = (⁸C₁ × ⁵C₁)/²⁰C₂
= (8 × 5)/190
= 40/190
= 4/19.
Hence, option(4) is correct.