**Rate of Interest is 5%**

Principal (P) = 6000

Amount (A) = 6615

no. of years (n) = 2

Let 'r' be rate of interest.

Compound Interest formula:

**A = P (1+r/100)^n**

6615 = 6000(1+r/100)^2

6615/6000 = (1+r/100)^2

(6615/6000)^(1/2) = 1+r/100

1.05 = 1+r/100

r/100 = .05

**r = 5%**