The average of 11 observations is 60. If the average of first five observations is 58 and that of the last five is 56, then the sixth observation is. Choose the correct choice from the following answers:
A) 85	B) 90	C) 100	D) 110	E) None of these
Explanation :   Sixth observation=[60*11 - (58*5 + 56*5)= 
<gadget id="calculator">60*11 - (58*5 + 56*5)</gadget>
<output>90</output>
90.   Answer : 90
<result>B</result>
The average of 11 observations is 60. If the average of first five observations is 58 and that of the last five is 56, then the sixth observation is.