Can 18 over 189, 24 over 189, 56 over 189 all be reduced ?

The general form of the quetion of a circle is ax^2+by^2+cx+dy+e=0 where a=b=0 if the circle has a radius of three units and the center lies on the y axis which set of values of a, b, c, d, and e might correspond to the circle

Student price tickets to a movie are $1 and non student tickets are $2. 350 tickets are sold and the total amount made is $450. how many non student tickets were sold ? a) 100 b) 150 c) 200 d)250

Aball is dropped from a height of 10m above the ground. it bounce to 90% of its previous height on each bounce. what is the approximate height that the ball bounce to the fourth bounce?