Question

The difference between the circumference and radius of circle is 111. cm . The diameter of the circle is
( i ) 21 cm
( ii ) 35 cm
( iii ) 42 cm
( iv )49 cm
please solve this problem.

Answer 1

Answer:

(iii) 42 cm

Step-by-step explanation:

Let the radius of the circle be r, such that,

$2\pi r-r=111 \\ \\ r(2\pi-1)=111 \\ \\ r(2 \times\frac{22}{7}-1)=111 \\ \\ r(\frac{44}{7}-1)=111 \\ \\ r \times \frac{37}{7}=111 \\ \\ r=111 \times \frac{7}{37} \\ \\ r=3 \times 7 \\ \\ r=21 \\ \\ 2r = \bold{42}$

So the answer is option (iii).

Thank you...

Answer 2

According to question:-

circumference - radius = 111cm

2πr - r = 111

r(2π -1) = 111

r = 111/(2π-1)

r = 111(2*22/7-1)

r = 111( 44/7-1)

r = 111( 37/7)

r = 111* 7/37

r = 3*7

r = 21 cm.

Diameter = 2 r

= 2*21 => 42 cm. Ans.

option iii) is the correct answer dude!!!!!