A sum of Rs 1200 amounts to Rs 1740 in 3 years at simple interest. If rate of interest is increased by 3%, then what will be the new amount (in Rs)?

Principal sum = Rs. 1200 and amount after 3 years = Rs. 1740

Let rate of interest = $$4r\%$$

Amount under simple interest = $$P+(\frac{P\times R\times T}{100})$$

=> $$1200+(\frac{1200\times r\times3}{100})=1740$$

=> $$36r=1740-1200=540$$

=> $$r=\frac{540}{36}=15\%$$

Thus, new rate of interest = $$15+3=18\%$$

$$\therefore$$ New amount = $$1200+(\frac{1200\times18\times3}{100})$$

= $$1200+648=Rs.$$ $$1848$$

=> Ans - (A)