A person lends 40% of his sum of money at 15% per annum,

Home » Aptitude » Simple interest » Question

A person lends 40% of his sum of money at 15% per annum, 50% of rest at 10% per annum and the rest at 18% per annum rate of interest. What would be the annual rate of interest, if the interest is calculated on the whole sum ?

1. 13.4%
2. 14.33%
3. 14.4%
4. 13.33%

Correct Option: C

Let the person have ₹ 100.
Then

SI for 1 year = ₹		40 × 15 × 1	+	30 × 10 × 1	+	30 × 18 × 1
		100		100		100

SI for 1 year = ₹ (6 + 3 + 5.4) = ₹ 14.4
∴ Rate of interest on whole sum = 14.4%