MHB Solving Probability w/ Cards: Answers & Explanations

[CosmoK123456]

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= .028If 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= .023265Thanks for the help!

 

[Plato2]

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]

I would also recommend reducing the fractions before applying the special multiplication rule. Keeping it simple reduces the risk of error. :D