6.
a. P(2 or 4) is the probability of rolling either a 2 or a 4 on the die.
P(2 or 4) is equal to P(rolling a 2) + P(rolling a 4)
1/6 + 1/6 = 2/6 = 1/3
b. P(greater than 2) is equal to P(3) + P(4) + P(5) + P(6)
1/6 + 1/6 + 1/6 + 1/6 = 4/6 = 2/3
7. The probability of getting a head is 1/2. If you toss the coin two times, there are four different possibilities. HH, TT, HT, or TH. The answer would be 1/4, you get that by multiplying 1/2 by 1/2 again.