A rectangle has 20 cm as its length and 200 sq cm as its area. If the area is increased by \( \Large \Large 1\frac{1}{5} \) times the original area by increasing its length only then the perimeter of the rectangle so formed (in cm) is


A) 72

B) 60

C) 64

D) 68

Correct Answer:
D) 68

Description for Correct answer:

\( \Large l_{1} \) = 20 cm, \( \Large A_{1} \) = 200 sq cm

\( \Large b_{1} \) = \( \Large \frac{200}{20} \) = 10 cm

Now,\( \Large A_{2} \) = \( \Large 200\times 6/5 \)= 240 sq cm

\( \Large b_{2} \) = 10 cm

\( \Large l_{2} \) = \( \Large \frac{240}{10} \) = 24 cm

Perimeter of new rectangle = 2(\( \Large l_{2}+b_{2} \))

= 2(24+10)= \( \Large 2\times 34 \)=68cm.


Part of solved Area and perimeter questions and answers : >> Elementary Mathematics >> Area and perimeter








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