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# Probability

0
540
1
+101

Tiles numbered 1 through 20 are placed in a box. Tiles numbered 11 through 30 are placed in a second box. The first tile is randomly drawn from the first box. The second tile is randomly drawn from the second box. Find each probability.

1. P(both are greater than 15)

2. The first tile is odd and the second tile is less than 25.

3. The first tile is a multiple of 6 and the second tile is a multiple of 4.

4.  The first tile is less than 15 and the second tile is even or greater than 25.

Jun 8, 2017

#1
+94513
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1. P(both are greater than 15)   =  (5/20) (15/20)  =  (1/4) (3/4)  =  3/16

2. The first tile is odd and the second tile is less than 25  =

(10/20) (14/20)  =

(1/2) (7/10) =

7/20

3. The first tile is a multiple of 6 and the second tile is a multiple of 4 =

(3/20) ( 5/20) =

(3/20) (1/4) =

3/80

4.  The first tile is less than 15 and the second tile is even or greater than 25

Let's look at the second one...it's a little tricky

Number ( even or > 25)  =

Number(even) + Number (.>25) - Number (even and > 25)

10             +          5              -          3

=        12

So we have

(14/20) ( 12/20)  =

(7/10) (3/5) =

21 / 50

Jun 9, 2017