MEDAL!

Two cards are selected from a deck of ten card from 1-10. Once a card is selected, it is not replaced. What is the probability that the first card selected is less than 5 and the second card is 5 or more?

Question

MEDAL!

Two cards are selected from a deck of ten card from 1-10. Once a card is selected, it is not replaced. What is the probability that the first card selected is less than 5 and the second card is 5 or more?

calculusxy · Answer

@jim_thompson5910

calculusxy · Answer

@ganeshie8

calculusxy · Answer

@agent0smith

calculusxy · Answer

$$\frac{ 5 }{ 10 } \times \frac{ 5 }{ 9 }$$

calculusxy · Answer

Is that the correct expression?

jim_thompson5910 · Answer

"What is the probability that the first card selected is less than 5"

that's 4/10 since there are 4 numbers (1,2,3,4) that are less than 5 out of 10 total

calculusxy · Answer

$$\frac{ 4 }{ 10 } \times \frac{ 5 }{ 9 }$$

jim_thompson5910 · Answer

"and the second card is 5 or more"

the numbers 5,6,7,8,9,10 are 5 or more. There are 6 of these numbers

out of 10-1 = 9 total

calculusxy · Answer

So my expression is correct right?

calculusxy · Answer

It would be 20/90 = 2/9

jim_thompson5910 · Answer

it should be (4/10)*(6/9)

calculusxy · Answer

Why 6?

calculusxy · Answer

Yes

jim_thompson5910 · Answer

the numbers 5,6,7,8,9,10 are 5 or more. There are 6 of these numbers

calculusxy · Answer

Uh...I felt like I forgot to count :(

calculusxy · Answer

so:
4/10 x 6/9

calculusxy · Answer

That's correct right?

jim_thompson5910 · Answer

correct, you'd multiply and reduce