cards, numbers, and coins probability!?

Question

a) if two cards are drawn without replacement from a standard 52-card deck, what is the probability that both cards are the same suit?

b) if two numbers are selected without replacement from the set (1,2,3,4,5) what is the probability that oth numbers are odd?

c) if four coins are tossed, what is the probability that the result will be all tails?

Answer 1

The first card can be any suit.
Once the first card is picked, then the second card has ? chance, out of the remaining 51 cards, of being the same suit as the first (a little less than a quarter, as expected).

b) the first number must by any 3 of 5, the second number must be any 2 of 4. Both events must occur, therefore we multiply the individual probabilities.

c) each coin has a 1/2 probability of being tails. All four events must occur, therefore we multiply the individual probabilities.

Answer 2

(a) Draw the first card. Anything will do. Now draw the second card. There were 51 to draw from, 12 of them the same suit as your first card, and 39 different. If all 51 cards are equally probable - yes, of course they are - then the probability of both being the same suit is 12/51.

(b) Select the first number. There are 3 out of 5 that will do. When you select the second number, there are 4 left to select from, two odd and two even. The probability of both selected numbers being odd is the probability of the first being odd, multiplied by the probability of the second being odd - that's 3 / 5 times 2 / 4, or 3 / 10 altogether.

(c) Toss them one after the other, because the answer is the same. Probability of tails on the first = 1 / 2, on the second = 1 / 2, . . . multiply them all together, surely you've got the hang of it by now.

Answer 3

a) OK, this one is simple...the first card has a 1/1 probability of being any suit...and the second card has a 12/51 probability of being the same = 12/51 is the answer

note: if the question said what is the probability of being a club (or heart, spade, diamond) then it is 13/52 * 12/51

b) 3/5 *2/4 = 3/10

c) (1/2) exponent 4...in other words 1/2*1/2*1/2*1/2 = 1/16

Answer 4

quantity a million 50/50 2 opportunities in a million tyr. quantity 2 a million-6 are the numbers of each cube so with out even questioning the end results of two-rolls is a heavt prominent to be 6+. the coolest atypical are basic math. quantity 3 as quickly as back numbers and branch - it boils right down to ace - 10 and the three face enjoying cards j ok q so 3.33333333333333333333333333333333333333... divided by potential of 50/50

Answer 5

[a] 13/52 * 12/51 = ?

[b] 3/5 * 2/4 = ?

[c] 1/2 * 1/2 * 1/2 * 1/2 = ?