Out of seven given numbers, the average of the first four numbers is 4 and that of the last four numbers is also 4. If the average of all the seven numbers is 3, fourth number is  Choose the most appropriate option:
A) 3
B) 4
C) 7
D) 11
E) 12
(a+b+c+d)/4=4   =&gt;(a+b+c+d)=16...........(1)   (d+e+f+g)/4=4   =&gt;(d+e+f+g)=16   =&gt;(e+f+g)=16-d...........(2)   Also, (a+b+c+d+e+f+g)/7=3 (Given)   using (1) and (2) equations   16+16-d=21   =&gt; d=11   ANSWER:11
<result>D</result>
Out of seven given numbers, the average of the first four numbers is 4 and that of the last four numbers is also 4. If the average of all the seven numbers is 3, fourth number is