Mensuration Ques 38
Question
The area of first circle and circumference of second circle are $1386 cm^{2}$ and $176 cm$ respectively. There is a square whose side is $35 \frac{5}{7} \%$ of twice the sum of the radius of both the circles. Find the perimeter of the square (in $cm$ )?
(1) 132
(2) 136
(3) 140
(4) 116
(5) 124
(IBPS RRBs Officer CWE (Prelim Exam) 04.08.2019)
Show Answer
Correct Answer: (3)
Solution: (3)
Radius of first circle $=r_{1} cm$.
$\therefore \pi r_{1}^{2}=1386$
$\Rightarrow \frac{22}{7} \times r_{1}^{2}=1386$
$\Rightarrow r_{1}^{2}=\frac{1386 \times 7}{22}=441$
$\Rightarrow r_{1}=\sqrt{441}=21 cm$.
Radius of second circle $=r_{2} cm$.
$\therefore 2 \times \frac{22}{7} \times r_{2}=176$
$\Rightarrow r_{2}=\frac{176 \times 7}{2 \times 22}=28 cm$.
$\therefore$ Side of square $=2\left(r_{1}+r_{2}\right) \times \frac{250}{700}$
$=2 \times(21+28) \times \frac{25}{70}$
$=\frac{2 \times 49 \times 25}{70}=35 cm$.
$\therefore$ Perimeter of square $=4 \times 35=140 cm$.
BETA
