Suppose that the actual F two distribution was as follows instead of having this hypothetical distribution because crossing over does take place we produce this distribution. So notice that now not only do we have the gray and wingless and the black and winged as we have in this case we also have the gray winged and the black winged. And these two here are actually the recombinant offsprings and they are produced as a result of crossing over as a result of the production of recombinant chromosomes. So we are given that eight, nine, five are gray wingless, 905 are black wing but 110 are gray wings and 90 are black wingless. To make a total of if we sum these up, we obtain 2000 offspring. So the question is what is the recombination frequency between the two traits the color traits and that wing type trait?