What do individuals who are heterozygous for codominant traits show for a
phenotype?

Individuals who are heterozygous for co-dominant traits show in their phenotype both traits, without mixing.

Explanation:

Codominance is a type of inheritance that does not follow the rules of Mendelian inheritance, characterized by the absence of recessive traits and two different alleles for a character that behave as dominant.

Heterozygous individuals can be observed in codominance that show two different characteristics in their phenotype, without mixing, such as cattle with spotted skin or two colored flowers.

9.9 years

a = p(1 + rt) . . account balance after time t at rate r starting with principal p

3000 = 2500(1 + 0.0202t) . . filling in the given numbers

1.2 = 1 + 0.0202t . . divide by 2500

0.2 = 0.0202t . . . subtract 1

0.2/0.0202 = t ≈ 9.901

it will take about 9.9 years for the account balance to reach $3000.