Genetics and monohybrid crosses

Question

In gerbils red fur (R) and tan fur (T) are co-dominant. A record of gerbil offsprings show 50% had tan fur. None of the offsprings had red fur only. What is the most likely parent cross/ genotypes?

Answer 1

F1 = TT x TR

F2 = TT, TT, TR, TR

This is good because 2 out of the 4 (50%) would be TT (tan color). Only RR would be red, and the problem specified none would be all red.