If a man receives on one-fourth of his capital 3% interest, on two third 5% and one the remaining 11%, the percentage interest he receives on the whole is :

Let the total capital = 1200
According to the question,
one-fourth of 1200 = 300, two third of 1200 = 800, remain 100
Interest on 300 = 3% of 300 = 9
Interest on 800 = 5% of 800 = 40
Interest on 100 = 11% of 100 = 11
Total interest = (9 + 40 + 11) = 60
Required percentage :
= $$\frac{60}{1200}$$ × 100
= 5%