What is a man's probability of living within 10 years is 2/3 and his wife's probability of living within 10 years is 4/5. Find the probability of:

a. Both live
b. Probability that one lives at least

Help my friends! it's urgent :)

Question

What is a man's probability of living within 10 years is 2/3  and his wife's probability of living within 10 years is 4/5. Find the probability of:

a. Both live 
b. Probability that one lives at least 

Help my friends! it's urgent :)

ganeshie8 · Answer

For both living, simply multiply the probabilities

crisulcampo · Answer

you mean 4/5 * 2/3 ?

ganeshie8 · Answer

Yes, simplify

crisulcampo · Answer

what about the part B?

ganeshie8 · Answer

First find the probability for both not living

ganeshie8 · Answer

Man's probability for living is 2/3
so, man's probability for not living = 1 - 2/3 = ?

crisulcampo · Answer

1/3 for him and 1/5 for her

ganeshie8 · Answer

Those are the probabilities for not living for each

crisulcampo · Answer

then?

ganeshie8 · Answer

Multiply them both to get the probability for both not living

crisulcampo · Answer

So, I get 1/15

ganeshie8 · Answer

That's the probability for both of them not living

crisulcampo · Answer

Yes, it is

ganeshie8 · Answer

You must know what to do next to get the probability that at least one lives

crisulcampo · Answer

Should I sustract from both's probability of living?

ganeshie8 · Answer

Subtract 1/15 from 1

crisulcampo · Answer

OMG! of course! thanks my friend... I don't know what I would have done without you

ganeshie8 · Answer

yw :)

crisulcampo · Answer

that one I substract from represents both's probability of living in 10 years?

ganeshie8 · Answer

1/15 is the probability for both of them not living

ganeshie8 · Answer

what is the "opposite" of both living ?

crisulcampo · Answer

both dying

ganeshie8 · Answer

Nope. Think again.

crisulcampo · Answer

at least one died?

ganeshie8 · Answer

Exactly!

ganeshie8 · Answer

Let's do a quick example

ganeshie8 · Answer

What's the opposite of "passing both subjects" ?

crisulcampo · Answer

I think the direct opposite is both living subjects. However, you can let it with no sense saying that at least one lives

ganeshie8 · Answer

Suppose you have to pass both subjects in order to pass a course.
What happens if you fail at least one subject ?

crisulcampo · Answer

I don't pass

crisulcampo · Answer

it's a condition

crisulcampo · Answer

it must be accomplished, one depending on another

ganeshie8 · Answer

That should convince us that the opposite of "passing both subjects" is "failing at least one subject".

crisulcampo · Answer

could you help me with other excercise?

crisulcampo · Answer

it has the answer

ganeshie8 · Answer

I'll try. Please open a new question and tag me

crisulcampo · Answer

ok