A jar contains 9 red marbles numbered 1 to 9 and 7 blue marbles numbered 1 to 7. A marble is drawn at random from the jar. Find the probability that the marble is blue or even-numbered.

To find the probability that the drawn marble is blue or even-numbered, we need to determine the number of favorable outcomes and the total number of possible outcomes.

Step 1: Determine the number of favorable outcomes
The favorable outcomes in this case are the marbles that are blue or even-numbered.
- There are 7 blue marbles in the jar.
- There are 4 even-numbered red marbles (2, 4, 6, 8) and 3 even-numbered blue marbles (2, 4, 6).

Therefore, the total number of favorable outcomes is 7 + 4 + 3 = 14.

Step 2: Determine the total number of possible outcomes
The total number of possible outcomes is the sum of all the marbles in the jar.
- There are 9 red marbles numbered 1 to 9.
- There are 7 blue marbles numbered 1 to 7.

Therefore, the total number of possible outcomes is 9 + 7 = 16.

Step 3: Calculate the probability
The probability is the ratio of the number of favorable outcomes to the total number of possible outcomes.

Probability = Number of Favorable Outcomes / Total Number of Possible Outcomes

Probability = 14 / 16 = 7 / 8

Therefore, the probability that the marble drawn from the jar is blue or even-numbered is 7/8 or 0.875.