It should be 130 as from day one to day two and to day three it goes up by 10 so 12*10+10
6/54 times because there are 9 marbles and the orange marble is 1 out of those 9 marbles. If you multiply 6*9= 54 then you notice there is a 6/54 chance of picking any 1 marble out of the 54 times that you decide to pick marbles.
-43 - 4r = 3 - 27r
Add 27r to both sides. -43 - 4r + 27r = 3 -27r + 27r or -43 + 23r = 3
Add 43 to both sides. -43 + 43 +23r = 3 + 43 or 23r = 46.
Divide both sides by 23 to get r by itself. 23r / 23 = 46 / 23 or r = 2
r = 2