I believe you would do 2 times 3, which gives you 6. 3 is for the number of coin tosses, and 2 is the number of sides of a coin.
6+6=12 + 6= 18
6x3=18
(I feel like u know the answer, just asking to give away free points. Either way the answer is 18 and thank you.)
162/(6(7-4)^2)
pemdas
parenthasees inner first
so 7-4 is forst
7-4=3
162/(6(3)^2)
then exponents
3^2=9
162/(6(9))
multiplication
6 times 9=54
162/(54)=3
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