Three blocks of different colors are to be placed on a row. How many different sitting arrangements are possible if red must be placed next to blue ? Select.
A) 2	B) 4	C) 6	D) 8	E) 10
Consider red and blue as one. But, in this arrangement they can be placed in two different combinations.   Red first and Blue second or blue first and red second.   Total we have (R and B) and third color = 2 arrangements to do.   Total arrangements= 2*2= 
<gadget id="calculator">2*2</gadget>
<output>4</output>
4   4 is the answer
<result>B</result>
Three blocks of different colors are to be placed on a row. How many different sitting arrangements are possible if red must be placed next to blue ?