A) you can combine any of the 5 ice-creams with any of the 3 toppings and any of the 4 drinks.
This means a total of 5*3*4=60 ways.
B) assuming that the first digit can be 0, we have 10 choices for the 1. digit, 9 for the 2., 8 for the third and 7 choices for the fourth digit.
In total, there are 10*9*8*7=5040 passwords we can create.
C) Selection of 3 objects out of 8, can be done in
C(8, 3)=8!/(3!5!)=(8*7*6)/3!=8*7=56 many ways.
D.
P(prime)=n(prime)/n{1, 2, 3, 4, 5, 6}=n{2, 3, 5}/6=3/6=1/2=0.5
E.
any of the 6 outcomes of rolling a die, can be combined with any of the 4 colors.
for example (1, red), (1, yellow), (1, green), (1, blue).
so in total, there are 6*4=24 items in the sample space.
F.
(5, red) is just one of the 24 items in the sample space, so its probability is 1/24= 0.0417
G.
the mode, as it is the size which appears the most.
Answers:
A.60
B.5040
C.56
D. 0.5
E.24
F.1/24= 0.0417
G.mode