The height of a tree increases $$\frac{1}{8}$$ times every year. If the present height of the tree is 64 cm, then what will be its height after 2 years?​

Correct option is C

Given:

The height of a tree increases $$\frac{1}{8}$$​ times every year.

The present height of the tree is 64 cm.

Solution:

Height after 2 years = Present height × Growth factor²

= 64 × $$\left(\frac{9}{8}\right)^2$$​​

= 64 × $$\frac{81}{64}$$​​

= 81 cm

∴ The height of the tree after 2 years is 81 cm. 

Alternative Method: 

Present Height : Height after two years 

(8)²        :    (9)²  

          64          :     81  

According to the question 64 unit = 64 cm 

Then the height after two years = 81 unit = 81 cm