Question

There're some old video games you sell on Ebay for $6, $7 and $9. The titles include " The Pirates", "Under the sea" and "The driving test". What is the Probability of selling video games with no water theme for at least $7?

Answer 1

2/9

Explanation:

lets create a sample space

so

the pirates can be sold for $7 $6 or $9

p

6 7 9

under the sea can be sold for $6 $7 or $9

S

6, 7, 9

driving test can be sold for $6 $7 or $9

D

6, 7, 9

here are all the combinations:

p,6

p,7

p,9

s,6

s,7

s,9

d,6

d,7

d,9

since out of 9 combinations driving test is the only one that is not water related lets look at that. There are only 2 combinations of driving test which are less than or equal to $7, (d,7 and d,6) hence the probability of selling no water games for less than $7 is 2/9

Answer 2

2/9

Explanation:

We have 3 video games

I will assume that pirates have a water theme, so 2 have a water theme

That leaves 1 game with no water theme

P (no water theme) = games with no water theme/ total

=1/3

The games are 6 7 and 9 dollars

2 games are at least 7 dollars

P( at least 7 dollars) = games at least 7/ total

=2/3

P ( no water theme at least 7 dollars) = P (no water theme) * P( at least 7 dollars)

= 1/3*2/3

= 2/9