Question

a homozygous dominant brown mouse is crossed with a heterozygous mouse tan is the recessive color

Answer 1

1/2 will be homozygous dominant brown and the other half will be heterozygous for brown 

Answer 2

22 is x=32 and 23 is 2.5 inches. You just cross multiply for 22 and divide for 23 like you see in my work shown.