Find the time in which ₹ 1,200 will amount to ₹ 1,536 at 3.5% per year.

Given:

P = ₹ 1,200

R = 3.5%

A = ₹ 1,536

As we know,

∵ A = P + S.I.

⇒ ₹ 1,536 = ₹ 1,200 + S.I.

⇒ S.I. = ₹ 1,536 - ₹ 1,200

⇒ S.I. = ₹ 336

Let time be $t$ years.

$\because \text{S.I.} = \Big(\dfrac{P \times R \times T}{100}\Big)\\[1em] \Rightarrow \text{336} = \Big(\dfrac{1,200 \times 3.5 \times t}{100}\Big)\\[1em] \Rightarrow \text{336} = \Big(\dfrac{4,200t}{100}\Big)\\[1em] \Rightarrow \text{336} = 42t\\[1em] \Rightarrow t = \dfrac{336}{42}\\[1em] \Rightarrow t = 8$

Hence, the time is 8 years.