<h3>Straightforward Solution</h3>
The long way around is to compute the return from each investment and relate the sum of those returns to the toal investment.
You have invested $33×100 = $3300 in clooney. You expect a return of 20%×$3300 = $660 on that investment.
You have invested $42×100 = $4200 in marx. You expect a return of 12%×$4200 = $504 on that investment.
Your total expected return is $660 + 504 = $1164. Your total investment is $3300 + 4200 = $7500. Thus, the return on your investment is expected to be
... $1164/$7500 = 0.1552 ≈ 15.5% . . . . matches choice a.
<h3>Alternative Solution</h3>
Since the same number of shares is involved in both investments, you can weight the expected return percentages by the ratio of share price to total of share prices:
expected return = (33/75)×20% + (42/75)×12%
... = 8.80% + 6.72% = 15.52%
