In what time will the simple interest on 1200 Tk. at 4% per annum be the same as that on 600 Tk. at 8% per annum in 2 years?

Question: In what time will the simple interest on 1200 Tk. at 4% per annum be the same as that on 600 Tk. at 8% per annum in 2 years?

Solution:
the interest of 600 Tk. at 8% per annum in 2 years is = 600 × 2 × 8%
= 96 Tk.

let, the time is n years.
I = 96 Tk.
P = 1200 Tk.
r = 4%

as we know,
I = Pnr
n = I / Pr
= 96 / (1200 × 4%)
= 2 years