Question

Find the diameter of the circle if the circumference of the circle is  \(\frac {11}{5}\)m.

(a) 23.07 cm

(b) 20.74 cm

(c) 72.33 cm

(d) 70 cm

I had been asked this question in an interview for job.

Question is taken from Perimeter and Area of a Circle topic in division Area Related to Circles of Mathematics – Class 10

Answer 1

Correct choice is (d) 70 cm

Explanation: The circumference of the circle = \(\frac {11}{5}\)m

2πr = \(\frac {11}{5}\)m

πd = \(\frac {11}{5}\)m     (∵ Diameter = 2 × radius)

d = \(\frac {11}{5} \times \frac {7}{22}\)m

d = 0.7 m

d = 0.7 × 100 cm

d = 70 cm