In Mendel's dihybrid cross experiment,how many types of genotypes are obtained in the $F_2$ generation?

The phenotypic ratio of a dihybrid test cross performed by Mendel is ....

In Mendel's dihybrid cross,what percentage of the total $F_2$ progeny had green seeds (in $\%$)?

In Duroc-Jersey hogs,skin color is determined by two pairs of alleles,$R/r$ and $S/s$. Any genotype containing at least one dominant $R$ allele and one dominant $S$ allele results in a red skin color. $A$ double recessive genotype $(rrss)$ results in a white skin color. All other genotypes result in a sandy skin color. If a Duroc-Jersey hog with the genotype $RrSs$ is crossed with a hog having the genotype $rrss$,what will be the phenotypic ratio of the offspring?

When $AABB$ and $aabb$ are crossed,in $F_2$ generation the ratio of $AaBb$ will be (in $/16$)

In a dihybrid cross between $RRYY$ and $rryy$,the number of $RrYy$ $F_2$ genotypes will be