In your you not mentioned number of shares so I am considering number of shares is 200.
Other can't answer this question.
Investment on 1 share = ₹ (25 + 20) = Rs 45
Investment in buying 200 shares = ₹ (200×45) = Rs 9000
Rate of dividend = 12%
Income on 1 share =12%of₹25 =(12100×25)=₹ 3
Income on 200 shares =₹(200×3)=₹600
Therefore percentage return on his investment =TotalincomeTotalinvestment×100
=(6009000×100)%=6.67%