make -4 1/5 and improper fraction which would be -21/5x1/3 then u multiply across and ur answer is -21/15. Then you havw to change it to a mixed number and you would get 1 6/15. This number can be simplified by 3 so it would be - 1 2/5
After the 3rd pick we have: 4 white, 3 red and 8 black marbles. The probability that the 4th marble is black is: P ( Black ) = 8 / 15 = 0.5333 After the 4th pick we have: 4 white, 3 red and 7 black marbles. P ( Red or Black ) = 10 / 14 = 5 / 7 = 0.7143
