If the arcs of a same length in two circles subtend angles of $$60°$$ and $$75°$$ at their centres, the ratio of their radii is

Let the length of the circle be 'L"
Angle of the circle1 =60°
Angle of the circle2 =75°
Let the radius be $$r_{1}$$ and $$r_{2}$$
L = $$r_{1}$$θ
$$r_{1}\times60\times\frac{π}{180}$$
$$r_{1}\times\frac{π}{3}$$
$$L=r_{2}\times\theta$$
$$r_{2}\times75\times\frac{π}{180}$$
$$r_{1}\times\frac{5π}{12}$$
Since L is same for both the circles ,
$$r_{1}\times\frac{π}{3}$$ = $$r_{1}\times\frac{5π}{12}$$
$$r_{1}$$ : $$r_{2}$$ = 5 : 4