At a simple interest Rs.850 becomes Rs.1250 in 5 years. If the interest rate is increased by 5%, how much would Rs.850 become in 4 years?

Rs.1340

S.I. in 5 years = ₨.1250 - ₨.850 

                     = ₨.400

S.I, in 1 year = $\frac{400}{5}$ 

                   = ₨. 80

rate = $\frac{80}{850}$ x 100

       = 9.4 %

Now the rate is increased by 5% = 14.4%

Amount = P + $\frac{P\;×\;R\;×\;T}{100}$

             = 850 + $\frac{850\;×\;14.4\;×\;4}{100}$

             = 850 + 489.5

             = 1339.6 or 1340