Neeraj saves Rs. 400 at the end of each year and lends this saving at 5% p.a. compound interest, How much will it worth at the end of 3 years?

Amount after 3 years = 400(1 + 5/100)³ + 400(1 + 5/100)² + 400(1 + 5/100)
= 400(1+ 5/100) {1+ 5/100)² + (1 + 5/100) + 1 }
= 400(105/100) {(105/100)² + (105/100) + 1}
= 400(21/20) {(21/20)² + 21/20 + 1}
= 400(441/400 + 21/20 + 1)
= 400(441 + 420 + 400/400)
= 420(1261/400)
= Rs.1324.05