Step-by-step explanationFrom the statement, we have a hat with cards and the following probabilities for drawing each of the cards:
• P(yellow) = 1/25,
,
• P(black) = 1/15,
,
• P(red) = 1/20,
,
• P(purple) = 1/10.
Drawing a purple or a black card car are independent events so the probability of drawing a purple or a black card, so the probability is the sum of the individual probabilities:

Reducing the fraction, we have:

Answer
The probability of pulling a purple or black card is 1/6.