Question

The percentage increase in the area of a rectangle, if each of its sides is increased by 20%
A) 22%
B) 33%
C) 44%
D) 55%

Answer 1

↘↙↘↙⤵⤵↙↘↙↘↙

Answer:   C) 44% 

Explanation:

Let original length = x metres and original breadth = y metres.

Original area = xy sq.m 

Increased length  = 120100 and Increased breadth = 120100 

 

New area = 120100x*120100y=3625xy m2 

 

The difference between the Original area  and New area  is:  

3625xy-xy

 

1125xy Increase % =(1125xyxy)*100= 44%

Answer 2

The percentage increase in the area of a rectangle, if each of its sides is increased by 20%
A) 22%
B) 33%
C) 44%
D) 55%

Answer = Option C

Explanation:

Let original length = x metres and original breadth = y metres.

Original area = (xy) m2.

New length =(120/100x)m=(6/5x)m.

New breadth =(120/100y)m=(6/5y)m.
New Area =(6/5x × 6/5y)m2=(36/25xy)m2.
The difference between the original area = xy and new-area 36/25 xy is

= (36/25)xy - xy

= xy(36/25 - 1)

= xy(11/25) or (11/25)xy

Hence, Increase % =(11/25xy × 1/xy × 100)%= 44%.