There are 2 red chips and 2 blue ones. When arranged in a row, they form a certain color pattern, for example RBRRB. How many color patterns?  Choose the correct choice from the following options:  A) A)10  B) B)12  C) C)24  D) D)60  E) E)100
Using anagram method:   4_3_2_1   R_R_B_B   so..   4!/Number of repeated letters (2!)(2!) = 6   ANS:60
<result>D</result>
There are 2 red chips and 2 blue ones. When arranged in a row, they form a certain color pattern, for example RBRRB. How many color patterns?