Answer:
8/13
Step-by-step explanation:
There are total 26 red cards in the deck of 52 cards.
There are also 12 face cards in the deck ( which is 6 of them are red, while 6 of them are black)
Since we only need either one of them, 26 + 6 = 32
The probability of drawn a card that either red or a face card is 32/52
The simplest form of this fraction is 8/13.
Answer:
2.25
Step-by-step explanation:
The total frequency is:
20 + 12 + 6 + 2 = 40
Calculate the probability of each score:
P(X=3) = 20/40 = 0.50
P(X=2) = 12/40 = 0.30
P(X=1) = 6/40 = 0.15
P(X=0) = 2/40 = 0.05
So the expected value is:
E = (3)(0.50) + (2)(0.30) + (1)(0.15) + (0)(0.05)
E = 2.25
Lets get all the information we need first.
A week has 7 days, you practice 30 min each day, so in a week you will practice a total time t of 30 min for 7 times, that is:
t = 7day(30 min/day)
t = 210 min
So in a week you will practice a total of 210 minutes.
Answer:
350
Step-by-step explanation:
