Question

kay tears off labels of all 10 soup cans
her mother knows there are 2 tomato and 8 vegetable
she selects 4 at random. what is the probability

a. exactly one of the 4 cans is tomato
b. none of the 4 cans is tomato
c. at least one of the 4 is tomato?

Answer 1

a) 2C1/10C4

Answer 2

b) 2C0/10C4

Answer 3

c) (2C1 + 2C2)/10C4

Answer 4

i am very confused...and i know the answers to these problems...i just dont know how to do them?

Answer 5

on top of the fraction,the numerator is the no of ways o selecting 1 tomato can out of a possible 2 , and the denominator is the total no. of selections ie 10C4, selecting any 4 out of 10 cans

Answer 6

get it or nt?

Answer 7

no not really........the answer to the first is .8 so that is why i am confused

Answer 8

cant be

Answer 9

how?

Answer 10

10!
-------- sounds plausible?
2!(10-2)!

Answer 11

check my solution...shes sayin its 0.8 the answer

Answer 12

then it aint 45 lol

Answer 13

2 2 2 2
------- perchance?
10 9 8 7

Answer 14

combo and perms are still new to me :)

Answer 15

ha same

Answer 16

id have to draw up a tree or something and count them out lol

Answer 17

yeah...i am not sure if it is a combo though?
def probablility

Answer 18

its using combos

Answer 19

m 95% sure my methods right nelly

Answer 20

there are 45 ways to select 4 cans right? or did i mess that up too

Answer 21

10C4

Answer 22

10C4....what is that in longhand tho?

Answer 23

10!
--- ??
4!6!

Answer 24

10!/(6!4!)

Answer 25

210?

Answer 26

i got 120960?

Answer 27

10 9 8 7 6 5 4 3 2
----------------
4 3 2 6 5 4 3 2


10 9 8 7
--------
4 3 2


5 3 2 7 = 15(14) = 210 right?

Answer 28

yeah

Answer 29

so we have 210 ways to do this lol

Answer 30

great

Answer 31

how many ways can we have 2 tcans?

Answer 32

672

Answer 33

or is it easier to say how many ways to pick no tcans?

8 can ways then...

Answer 34

no no

Answer 35

pick one out of 2 cans is 2C1

Answer 36

but that doesnt gives us a total ways for tcans does it?

Answer 37

336

Answer 38

if there are 8 ways to choose 4 cans

8!
--- ??
4!4!

Answer 39

70?

Answer 40

8765432
--------
432.432

8765
-----
432


725 = 14*5 = 70

Answer 41

70/210 = 7/21 = 1/3; 33.33% ??

Answer 42

so the chance that 1 is at least a tcan could be 66' 2/3% does that seem reasonable?

Answer 43

33' 1/3% chance we got no tcans
66' 2/3% chance we got at least 1 tcan seems good to me

Answer 44

nope the anwser is .8 blah

Answer 45

.8 is 80%

which answer is .8? a,b or c?

Answer 46

10C4 is the total number of ways to choose 4 cans....

8C4 is the total number of ways to choose no tcans.... casue we removed them from the equation....

% = part/total

% = 8c4/10c4 for no tcans

100- no tcan% = at least 1 tcan....

is my reasoning

Answer 47

a

Answer 48

whats the answers to b and c :)

Answer 49

b .333333
c. .66666

Answer 50

yay!! i was right :)

Answer 51

exactly one of the 4 cans is tomato lets see if we take away one tcan; just for the sake of argument; we can do this then

Answer 52

9!
---- = 3.3.2.7 = 9(14) = 126 ways to possible ways to
4!5! to choose at least 1 tcan

Answer 53

i am still very confused how to do the first as i get 122/210 = .53333

Answer 54

126 ways for 1 possible tcan

and we still have 70 ways for no tcans..; i wonder

Answer 55

126-70 would give us the number of ways for 1 tcan right?

126
70
----
56 ways that at least 1 tcan is in it... i hope lol

Answer 56

56/210

.
---------
105/28.0000 ......not gonna be .8 lol