Question

The percentage increase in the area of a square, if its sides is increased by $25\%$.

• A.
  
• B.
  
• C.
  
• D. None of these

Answer 1

The correct option is A


Let the length of side square be 10 units
Its area = $(10units{)}^2$ = 100 sq. units
Now, sides increases by $25\%$
New side = 10 + 10 $\times$ $\frac{24}{100}$
= 10 + 2.5 = 12.5 units.
Change in area = $(12.5units{)}^2–(10units{)}^2$​
= 156.25 sq. units – 100 sq. units
= 56.25 sq. units
Percentage change = $\frac{56.25}{100}$ $\times$ $100\%$
= $56.25\%$