If the rate increases by 2%, the simple interest received on a sum of money increases by Rs. 108. If the time period is increased by 2 years, the simple interest on the same sum increases by Rs.180. The sum is ?

Let the sum be Rs. p, rate be R% p.a. and time be T years.

Then,

  $\frac{P\times T\times (R+2)}{100}-\frac{P\times T\times R}{100}=108 \Rightarrow 2PT= 10800 ...... \left(1\right)$

 And, 

  $\frac{P\times R\times (T+2)}{100}-\frac{P\times R\times T}{100}=180 \Rightarrow 2PR = 18000 ......\left(2\right)$

Clearly, from (1) and (2), we cannot find the value of p
So, the data is not sufficient.