Question

The ratio between the radii of two circles is 5 : 7. Find the ratio between their :

(1) circumferences
(2) areas

Answer 1

(1) will remain same 5:7
(2)ratio will be 25:49

Answer 2

A) 5:7
B)25:49
$\frac{2 \pi5x }{2\pi7x} = \frac{5}{7 } \: \: \: \frac{\pi25 {x}^{2} }{\pi49 {x}^{2} } = \frac{25}{49}$

the answers are here.