[Styx]

Lotto is simple game, you pick 6 numbers from 1-40. 6 Numbers you pick are called a line.
40 Balls are mixed into a barrel and 6 of them are randomly rolled out of the barrel. If your 6 match the 6 that came out, you win a big prize.

Some friends get together and pool enough money to buy lots of lines.
Remember a line is 6 numbers.

After 2 balls have rolled out, it turns out 136 of their lines have exactly one number correct (one out of the first numbers). This is exactly the number that you would expect from the number of lines they purchased.

Use this info to calculate how many lines they purchased and how many lines would be expected to have both the first 2 numbers correct.

SHOW WORKING

I know the answer, took me abit of thinking .-.

[Connor]

lol 2 balls

[Styx]

no .-.

[Jeffalo13]

Am I still at school ;o?

[Str8F335h]

Can't you just do your homework by yourself?

[Xrow]

Well..
First result: 1 out of 136
Therefore second would be: 2 out of 272
And of the first 40 balls in the cage was 1 was matching.
Therefore the second 40 should have 1 matching.
Therefore 2 in 40
If you combine them, you get 4 of 352.
Then if you divide by 2, you get 176.
Therefore the probability if now 2 in 176.
Then divide by two again and you get 88.
Therefore the probability is 1 in 88.
Therefore if you multiple 136 by 88 you get 11,968.
Then you divide 11,968 by 6.
Therefore the answer is 1994.

Put that as your answer and you will get it right.
:D

[Styx]

Can't you just do your homework by yourself?

Did I say this was homework sir? I've already done it, and probability is easy.
The real answer is:
Prob. of 1st=6/40x34/39=17/130.
2nd=exactly the same.
So prob of exactly 1 out of 1st 2 is=34/130=17/65 (Simplified)
Thus bought 520 lines.
17/65x520=136.
Prob. of both numbers:1/52
which:expectation of exactly 10 lines having both of the 1st 2 numbers.

>:[
I said I knew the answer Lone. Thus, not homework.