Please help as soon as possible

[rgeer]

Hello,

Please help me with this problem:

1) A box of identically shaped candies contains 3 chocolate, 4 butterscotch, and 2 berry. Claire closes her eyes and picks 3 candies. Find the probability that she will get:
a) 3 of the same kind
b) 1 of each kind
c) 2 butterscotch and 1 chocolate, in that order

Please get me started.

Thanks in advance,
Ryan

 

[tkhunny]

This is a very poorly worded problem statement. It REALLY needs more information.

1) Are all the "like" kinds in there together?
2) Does she pick three together?
3) Does she put them back after picking?

Let's ASSUME that the candies are randomly placed in the box or that they are selected randomly. Let's also ASSUME that she east them and does not put them back.

Build a tree.

c = chocolate
b = butterscotch
y = berry

First pick must be one of

c
b
y

Second pick must be

cc
cb
cy
bc
bb
by
yc
yb
yy

Third pick must be

ccc
ccb
ccy
cbc
cbb
cby
cyc
cyb
cyy
bcc
bcb
bcy
bbc
bbb
bby
byc
byb
byy
ycc
ycb
ycy
ybc
ybb
yby
yyc
yyb
yyy <== Whoops. Throw this one out. Not enough berry candies. This leave 26 possible outcomes. Count up the ones you want.

3 the same

ccc
bbb

Just 2

1 of each

cby
cyb
bcy
byc
ycb
ybc

Looks like 6

bbc?

bbc

Only one (1). Not a surprise.

 

[rgeer]

This is a very poorly worded problem statement. It REALLY needs more information.

1) Are all the "like" kinds in there together? Yes
2) Does she pick three together? Yes
3) Does she put them back after picking? Yes

Let's ASSUME that the candies are randomly placed in the box or that they are selected randomly. Let's also ASSUME that she east them and does not put them back.

Build a tree.

c = chocolate
b = butterscotch
y = berry

First pick must be one of

c
b
y

Second pick must be

cc
cb
cy
bc
bb
by
yc
yb
yy

Third pick must be

ccc
ccb
ccy
cbc
cbb
cby
cyc
cyb
cyy
bcc
bcb
bcy
bbc
bbb
bby
byc
byb
byy
ycc
ycb
ycy
ybc
ybb
yby
yyc
yyb
yyy <== Whoops. Throw this one out. Not enough berry candies. This leave 26 possible outcomes. Count up the ones you want.

3 the same

ccc
bbb

Just 2- so the probability is 2/26?

1 of each

cby
cyb
bcy
byc
ycb
ybc

Looks like 6- is the probability 6/26?

bbc?

bbc

Only one (1). Not a surprise. is the probability 1/26?

Thanks and please reply
Ryan