question_answer

Refer to Design B

The circumference of outer part (golden) is

A) 48.49mm

B) 82.2mm

C) 72.50mm

D) 62.86mm

Correct Answer: D

Solution :

Directions (iii-iv) We have, circumference of silver part = 44 mm \[\therefore \,\,\,2\pi r=44\] \[\Rightarrow \,\,\,\,r=\frac{44}{2\times \frac{22}{7}}=7\,\,mm\] \[\therefore \,\,\,\,R=r+3=7+3=10\,\,mm\] Circumference of golden part \[=2\pi R\] \[=2\times \frac{22}{7}\times 10\] = 62.86 mm