 
<translate> Jimlar lambobi bakwai = 7X9 = 63 Jimlar lambobi 3 na farko da na karshe 3 = 3 X 7 + 3 X 11 = 54 Lambar da ke tsakiya ita ce (63 - 54) = 9 Amsar ƙarshe: (C). <eng> The total of seven numbers = 7X9 = 63
The total of first 3 and last 3 numbers is = 3 X 7+3 X 11 = 54
So, the middle number is (63 - 54 ) = 9
The final answer: (C). 