question_answer

A and B are two fixed points 5 cm apart and C is a point onA5 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%

Correct Answer: D

Solution :

\[\because \] Increase in AC = 6% \[\therefore \] Increased \[AC=\frac{106}{100}\times 3=3.18\,\,\text{cm}\] \[\therefore \] Decreased CB \[=5-3.18=1.82\,\,\text{cm}\] \[\because \]       Decrease \[=2-1.82=0.18\,\,\text{cm}\] \[\therefore \] Percentage decrease\[=\frac{0.18}{2}\times 100=9%\]