This question relies on Bayes' theorem and conditional probability. We are trying to find the conditional probability $P(Y | X)$, where:

• $X$ = Event that ROE of Xela exceeds 20%
• $Y$ = Event that ROE of Yena exceeds 30%

Given in the question:

• $P(X) = 0.10$
• $P(Y) = 0.05$
• $P(X \cap Y) = 0.02$ (The joint probability that both occur)

The formula for conditional probability is: $P(Y | X) = \frac{P(X \cap Y)}{P(X)}$

$P(Y | X) = \frac{0.02}{0.10} = 0.20$