A sum amounts to rs.9680 in 2 years and to rs.10648 in 3 years compounded annually. Find the rate of interest and the principal.please explain how to do it.

i don't know if you understand but here is the method i can solve this by:-

note:- p is principal, R is rate, T is time, C.A. is compounded amount

(9680*R*T)/ 100 = 10648-9680 we take interest of third year by simple interest

(9680*R*1)/100 = 968 further simplyfing

9680/100 *R = 968 P*R/100 can also be written as P/100 *R

96.8*R= 968 dividing 9860 by100

R = 968/96.8 transposing

R= 10 rate found by solving 968/98.6

now,

p(1+R/100)^t= C.A. formulae of compund interest

p(1+ 10/100)²= 9680 putting the values we have

p(1+ 1/10)²= 9680 dividing numerater and denominater by 10

p(11/10)²= 9680 adding 1 to 1/10

p*11/10*11/10 = 9680 opennig the brackets

p*11*11= 9680*10*10 by cross multiplication we bring 10 on right hand side

p*121 = 968000 multiplying on both sides

p= 968000/121 transposing 121 to right hand side

p= 8000 solving and getting valu of p