The average of 11 numbers is 10.9. If the average of first six is 10.5 and that of the last six is 11.1 the sixth number is?  Options:
A) 9.7 B) 10 C) 10.5 D) 11.5 E) 12
Explanation:   1 to 11 = 11 * 10.9= 
<gadget id="calculator">11 * 10.9</gadget>
<output>119.9</output>
119.9   1 to 6= 6 * 10.5= 
<gadget id="calculator">6 * 10.5</gadget>
<output>63</output>
63   6 to 11= 6 * 11.1= 
<gadget id="calculator">6 * 11.1</gadget>
<output>66.6</output>
66.6   63 + 66.6= 
<gadget id="calculator">63 + 66.6</gadget>
<output>129.6</output>
129.6 – 119.9= 9.7   6th number = 9.7   Option 9.7
<result>A</result>
The average of 11 numbers is 10.9. If the average of first six is 10.5 and that of the last six is 11.1 the sixth number is?