The half-life of cobalt 60 is 5.3 years. what fraction of a sample remains after 21.2 years?
a.
one half
b.
one quarter
c.
one eighth
d.
one sixteenth

The correct answer is-

C) 75% purple-flowered and 25% white-flowered.

As per the information given in the question, genotypes of parent plants are-

Pp and Pp that is heterozygous dominant, which exhibit purple flowers.

This indicates that purple flower is a dominant trait that masks the expression of recessive trait.

A dominant trait ( depicted by capital letter allele) always masks the expression of recessive trait ( depicted by small letter allele).

When parent plants with heterozygous dominant ( having two different alleles that is dominant and recessive allele) genotype are crossed, they will produce 75% purple-flowered and 25% white-flowered plants.

Refer punnet square.