Two short haired guinea pigs are mated several time. out of 100 offsprings 25 of them have long hair.?

If long hair is a recessive trait, lets call it r, to express the trait the guinea pig must have two long hair alleles (rr). If short hair is dominant (RR as well as Rr) and two short hairs mate, then both their genotypes must be Rr because 25% of the time a long haired offspring is produced. If you know how to do the cross, you put R r along the top and R r along the side, you should get the top left box with RR, the top right and the bottom left with Rr and the bottom right with rr. I hope that helped!