Point B is the center of two concentric circles PQ equals 4.2 andPS equals 8.2 RS is tangent to the smaller circle in the court of the larger circle what is the length of RS to the nearest 10th

Really need on these. i have no idea what to do

There are 20 children in the cast of a class play and 8 of the children are boys of the boys 4 have a speaking part in the play and of the girls 8 do not have a speaking part in the play if a child from the cast of the place chosen at random what is the probability that the child has a speaking part

Polygon hh is a scaled copy of polygon gg using a scale factor of 1/4. polygon h's area is what fraction of polygon g's area?