At what rate percent per annum simple interest , will a sum of money triple itself in 25 year?

Let principal amount = P
As amount =3P, T=25 yr
∴ SI=3P-P=2P
∴ Rate R = (100 x SI)/(P x T)
where, SI= Simple Interest T = Time
= (100 x 2P)/(P x 25)=8%