A sum of money amounts to Rs 6690 after 3 years and to Rs 10 035 after 6 years on compound interest ...........

Explanation:

Let the sum be Rs.P.then
P(1+R/100)^3=6690…(i) and P(1+R/100)^6=10035…(ii)
On dividing,we get (1+R/100)^3=10025/6690=3/2.
Substituting this value in (i),we get:
P*(3/2)=6690 or P=(6690*2/3)=4460
The sum is rs.4460.

Hence, option 3 is the correct answer.