In a population of 200, the individuals with recessive phenotype are 98. What percent of individuals of the population would have both dominant and recessive alleles?

Individuals with both dominant and recessive alleles are heterozygotes.

${\mathrm{q}}^2=\frac{98}{200}=0.49$

$\mathrm{q}=\sqrt{0.49}=0.70$
Now that we have q, we can solve for p.
p + q = 1
p = 1- q
p = 1 - 0.7 = 0.3
Heterozygotes (2pq)
= 2 x 0.7 x 0.3
= 0.42