A box contains 4 red chips and 3 blue chips. If two chips are selected at random without replacement, what is the probability that the chips are different colors?
Options:	A) 1/2	B) 12/21	C) 7/12	D) 2/3	E) 7/10
Total selection ways: 7C2=7!/3!4!=21   Selecting one blue chip out of two: 3C1=3!/2!1!=3   Selecting one red chip out of four: 4C1=4!/1!3!=4   Thus, (3C1*4C1)/7C2=(3*4)/21=12/21=12/21
<result>B</result>
A box contains 4 red chips and 3 blue chips. If two chips are selected at random without replacement, what is the probability that the chips are different colors?