Question

the simple interest of a certain sum for 3 years at the rate of 8 p.c.p.a. is rs.720 then what is the principal?

Answer 1

I think SI = P x r x t
so 720 = 3x8xP
so P = 720 / 2x8
        =  720/16
        = 45

Answer 2

Let principal be P
SI=PRT/100
720=(P×8×3)/100
P=(720×100)/(8×3)
P=72000/24=3000