Answer: (3)
Let us consider after t year amount is equal.
Consider an equation.
\(800 + \frac{800\times 12\times t}{100}= 910 + \frac{910\times 10\times t}{100}\)⇒ 800 + 96t = 910 + 91t
⇒ 5t = 110
⇒ t = 22 years
∴ After 22 years the amount will be equal.