A and B are two fixed points 5 cm apart and C is a point on AB such that AC is 3 cm. If the length of AC is increased by 6%, the length of CB is decreased by :

A. 6%

B. 7%

C. 8%

D. 9%

Answer: Option D

Solution(By Examveda Team)

Original length of AB = 5 cm
Original length of AC = 3 cm
Original length of CB = (5 - 3) cm = 2 cm
New length AC :
= 106% of 3 cm
= $$\left( {\frac{{106}}{{100}} \times 3} \right)$$  cm
= 3.18 cm
New length of CB :
= (5 - 3.18) cm
= 1.82 cm
Decrease in length of CB :
= (2 - 1.82) cm
= 0.18 cm
∴ Decrease % :
= $$\left( {\frac{{0.18}}{2} \times 100} \right)\% $$
= 9%