In how many ways can 6 balls of different colours, namely black, white, blue, red, green and yellow be arranged in a row in such a way that the black and white balls ar never together?

Explanation

To solve the problem of arranging 6 balls of different colors (black, white, blue, red, green, and yellow) such that the black and white balls are never together, we can use the principle of complementary counting. Here is a step-by-step solution:

### Step 1: Calculate the total arrangements of the 6 balls without any restrictions.
The total number of arrangements of 6 different balls is given by the factorial of the number of balls.

\[ \text{Total arrangements} = 6! = 720 \]
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