Suppose ‘R’ and ‘r’ are the rate of interest on investments by Vimal and Puneet;

According to the given data:

26000 = A + [A × r × 3]/100

⇒ A × [1 + 3r/100] = 26000---- (1)

And

25920 = B × [1 + R/100]³---- (2)

DIVIDING both the equations:

$( \Rightarrow \frac{{{\rm{A\;}} \times {\rm{\;}}\left[ {1{\rm{\;}} + {\rm{\;}}3{\rm{r}}/100} \right]}}{{{\rm{B\;}} \times {\rm{\;}}{{\left[ {1{\rm{\;}} + {\rm{\;R}}/100} \right]}^3}}} = \frac{{26000}}{{25920}})$

Given that A : B = 4 : 3 and

R – r = 10

If we put these values in the EQUATION, we can get the values of R and r;

If we get the rate of interest, we can calculate the investments A & B too.

After GETTING the investments, we can also get the difference of interest amount.

∴ All the values can be DETERMINED.