math
posted by claire on .
4 numbers are drawn at random from 10 tiles numbered 09. what are the odds of drawing numbers 14 in any order.
the question is confusing me

the prob you will pick a correct first number = 4/10
the prob that the second one is correct = 3/9
etc
so the prob of drawing a 1,2,3, and 4
= (4/10)(3/)(2/8)(1/7) = 1/210
or
total number of ways of 'choosing' 4 specifics form 10 is C(10,4) = 210
only one of these will be the correct choice we want.
so prob = 1/120 
line << = (4/10)(3/)(2/8)(1/7) = 1/210 >>
should read
= (4/10)(3/9)(2/8)(1/7) = 1/210
and it looks like a transposed the digits in the last line
so prob = 1/210