Two balls are drawn at random from a bag containing 2 white, 3 red, 5 green and 4 black balls, one by one without, replacement. Find the probability that both the balls are of different colours.

Explanation

To solve the problem of finding the probability that both balls drawn from the bag are of different colors, we can follow these steps:

### Step 1: Determine the total number of balls
The bag contains:
- 2 white balls
- 3 red balls
- 5 green balls
- 4 black balls
...