There are two ways to solve this problem.
In the first method, you subtract the number of black and white marbles from the total, then divide by the total number of marbles to find the number of red marbles.
In the second method, you simply divide the number of red marbles by the total number of marbles to calculate the probability of pulling a red marble.
Using either method, the probability of Nicole pulling a red marble out of the bowl is 0.1 or 10%.