Answer:
First Winner Getting white box =

Second Winner Getting white box =

Both getting the white box =

Explanation:
Number of available colors = 4
Number of boxes of each color = 10
So total boxes available = 40
Number of white boxes = 10
Probability is defined as the ratio of favorable outcomes to total possible outcomes. In this case, getting a white box is favorable outcome, so number of favorable outcomes is 10 and total possible boxes are 40. So,
Probability that first winner will receive a white box =

After the first winner has been given his box, there are 39 total boxes remaining with 9 white boxes. So,
Probability that second winner will receive a white box =

The probability that both the winners will receive the white boxes will be the product of their individual probabilities i.e.
Probability that the first winner receiving a white box and the second winner also receiving a box of the same color =
