In the figure two semicircles are drawn at the centre of the large semicircle
as shown in the figure . A fine dot is placed into the figure without looking
into it.
a) If the radius of the smaller semicircle is taken as 'r', What will be the
radius of the larger semicircle ?
b) What is the probability of being the dot inside the shaded semicircles ?
c) What is the probability of being the dot outside the shaded semicircles ?
I need Answers with explanation , please