Question

A tree increases annually by 1/8 th of its height. By how much will it increase after 2 years, if it stands today 64 cm high?

(a) 72 cm

(b) 74 cm

(c) 75 cm

(d) 81 cm

Answer 1

Correct option is (d) 81 cm

Let the original height of the tree = x cm.

We know that 

final height = original height × (1 + rate)^time

Here the rate is 81​, time = 2yrs, original height = 64cm.

Then the height after 2yrs. = 64 × \((1 + \frac 18)\) cm²

\(= \frac{64 \times 81}{64} \) cm

= 81 cm.