The answer is 9 : 3 : 3 : 1
First, it must be taken into consideration that these two traits are not simple "one gene - two alleles", but there is an influence of several genes. However, let's imagine, for this question, that these are simple examples of dominant and recessive alleles of one gene.
R - dominant allele for right-handedness
r - recessive allele for left-handedness
RR - a right-handed individual
Rr - a right-handed individual (because R is dominant over r)
rr - a left-handed individual
E - dominant allele for free earlobes
e - recessive allele for attached earlobes
EE - an individual with free earlobes
Ee - an individual with free earlobes (because E is dominant over e)
ee - an individual with attached earlobes
Now, we have dihybrid parents. Since hybrid individuals are those that carry two different alleles of one gene, dihybrid individuals are those that carry two different alleles of two genes (di- means two).
So, the parents are Rr and Ee, which can represent as RrEe. For each gene, they can give either dominant or recessive allele.
Take a look at the attached image. There are total 16 genotypes of the children. The children that are right handed and possess free earlobes are marked with yellow color. There are in total 9 of them. The children that are right handed and possess attached earlobes are marked with green color. There are in total 3 of them. The children that are left handed and possess free earlobes are marked with blue color. There are in total 3 of them. At last, there is only one child (marked white) that is left handed and possess attached earlobes.