In mice, a male and female are mated, both with long ears. All female have long ears but half the males bave short ears and half have ong ears the mode of inheritance and what is the genotype of the parents?

If you have both parents with long ears and some of the offsprings have short ears, you can say both parents are heterozygous for this. Both have a dominant (long ear), and a recessive allele (short ear).

To prove this, you can draw a Punnett square, and you'll see the probabilities of the offsprings.