Answer: 7/26
Explanation:
Number of purple marbles = 6
Number of white marbles = 7
Total number of marbles = 13
The probability of first drawing a white marble will be = 7/13
The probability of drawing a purple marble the second time will be = 6/12 = 1/2
The probability that the first marble is white and the second one is purple will now be:
= 7/13 × 1/2
= 7/26
Note that since there are 13 marbles, when the first purple marble is drawn, there'll be 12 marbles left.