Question

formula for finding principal if rate and amount is given

Answer 1

Principal=(Amount * 100)/Rate * Time + 100

Answer 2

Amount = Principal + SI
⇒ A = P + SI
⇒ A = P + PTR/100
⇒ A = P(1 + TR/100)
⇒ P = A/(1 + TR/100)
⇒ P = 100A/(100+TR)