What is the probability of producing a pink-flowered plant?

You need to do the Punnet square. If you cross a Homogeneous Red plant, RR, crossed with a Homogeneous white plant, WW, you will get 1 outcome. Through the Punnet square you find out that you get all R. W in your first generation, R. W. being your pink co-dominant plant offspring. In the second generation, you Cross 2 of the Heterogeneous offspring R. W x R. W and get the 1:1:2 ratio of red : white : pink respectively.