what is the probability of getting either a black card or an ace in one draw from an ordinary deck of 52 cards?
I got 8/13
26/52 black cards + 4/52 aces=8/13
the answer that was marked correct is 7/13
What did I do wrong?
( 6 / 13 ) + ( 1 / 13 ) = ( 7 / 13 )
Can you see why?
If it ain't broke, fix it until it is.
No great discovery was ever made without a bold guess.
13 black spades (including the ace of spades),
13 black clubs (including the ace of clubs),
the ace of diamonds,
the ace of hearts,
= 13 + 13 + 1 + 1 =28
28/52 = 7/13
Last edited by OzMark (2013-06-12 01:10:28)