A sum of money becomes Rs. 6690 after three years and Rs. 10035 after six years on compound interest. The sum is?

Let the principal be P,then
P(1 + R/100)³ = 6690
And P(1 + R/100)⁶ = 10,035
Now, dividing (ii)by (i),we get
⇒ (1 + R/100)³ = 10035/6690 = 3/2
⇒ P x 3/2 = 6690
∴ P = (6690 x 2/3 ) = Rs. 4460