Answer: The required probability is 0.9.
Step-by-step explanation: Given that Anna is shopping for a new backpack. The probability that the backpack is pink is 0.7, the probability that it is canvas is 0.7 and the probability that it is pink and canvas is 0.5.
We are to find the probability that the backpack is either pink or canvas.
Let, 'A' and 'B' be the events that the backpack is pink and canvas respectively.
Then, according to the given information, we have

From the law of probability, we have

Therefore, the required probability that the backpack is either pink or canvas is 0.9.