Question

There are 20 lottery tickets and 5 of them are lucky. It is randomly picked 2 tickets. How many ways are there to pick up at least one lucky ticket? @PeterPan

Answer 1

and now the answer is 85!

Answer 2

Yeah, well...
Same thinking, almost :D
How many ways can you pick one lucky ticket, out of five?

Answer 3

I am kinda stuck on this one :/ how about you peter?

Answer 4

I can fly through it ^.^

Answer 5

5C1?

Answer 6

:D

Answer 7

im kind answering 5 question at once :D

Answer 8

And that's just 5, isn't it? :)

Answer 9

5c1 = 5

Answer 10

yes

Answer 11

And you multiply this to how many ways you can pick one not-lucky ticket, out of 15 (since there are 20-5 not-lucky tickets)

Answer 12

15C1=15?

Answer 13

That's right :)
So 5 x 15 = 75

Answer 14

yes, but the answer is 85

Answer 15

Relax. We haven't considered everything :P yet

Answer 16

We've only considered getting exactly one lucky ticket
So how about 2?

Answer 17

5C2=10

Answer 18

And add that to 75
:P

Answer 19

okay, thank you a lot:)