I had been asked this question by my college professor while I was bunking the class.
This interesting question is from Monohybrid Cross topic in division Mendelian Genetics of Cytogenetics
Best explanation: Here the parents are heterozygotes so the ratio of the progeny will be 1:2:1 for white: Andulasian: black. If there are 10 white then according to the ratio there should be 20 Andulasian fowls produced. If we consider the number of black fowls that would be 10.