Question

if rs 450 amount to rs 504 in 3 year how much will 615 amount to in 2.5 year at the same rate of interest

Answer 1

We know that a = p + prt/100 => 504 = 450 + 450 * r * 3/100 => 504 = 450 + 1350r/100 => 504 = 450 + 13.5r => 13.5r = 54 => r = 54/13.5,r = 4
Now according to your question our new principal is 615 and time = 2.5 yrs.then the amount = p + prt/100 => 615 + 615 * 4 * 2.5/100 => 615 + 61.5 = ₹676.5