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probability with cards

CosmoK123456

New member
Jul 26, 2013
4
I just want to make sure I have these answers right... if they are not can you please explain how to get the right answer. The wording of the question is what gets me confused with probability.
A box contains 50 index cards. One letter is written on each card. There are
5 cards with the letter A
5 cards with the letter E
7 cards with the letter H
10 cards with the letter M
3 cards with the letter S
20 cards with the letter T

If one card is selected, replaced, and a second card selected, determine:

a) p(both A)
I have: 25/2500 = .01

b) p(neither is a vowel)
I have: 70/2500= .028


If one card is selected, not replaced, and second card selected, determine:

a) p(both A)
I have: 20/2450= .008163

b) p(neither is a vowel)
I have: 57/2450= .023265


Thanks for the help!!!
 

Plato

Well-known member
MHB Math Helper
Jan 27, 2012
196
I just want to make sure I have these answers right... if they are not can you please explain how to get the right answer. The wording of the question is what gets me confused with probability.
A box contains 50 index cards. One letter is written on each card. There are
5 cards with the letter A
5 cards with the letter E
7 cards with the letter H
10 cards with the letter M
3 cards with the letter S
20 cards with the letter T

If one card is selected, replaced, and a second card selected, determine:

a) p(both A)
I have: 25/2500 = .01

b) p(neither is a vowel)
I have: 70/2500= .028
How the heck did you get get that?
There are 40 non-vowels.
 

MarkFL

Administrator
Staff member
Feb 24, 2012
13,775
I would also recommend reducing the fractions before applying the special multiplication rule. Keeping it simple reduces the risk of error. :D