Average of a,b and c is 11, average of c,d and e is 17 average of e and f is 22 and the average of e and c is 17 . Find out the average of a, b, c, d, e and f.

a + b + c = 11 x 3 = 33 .....(i)
c + d + e = 17 x 3 = 51 .....(ii)
e + f = 22 x 2 = 44 .....(iii)
e + c = 17 x 2 = 34 .....(iv)
From Eqs. (ii) and (iv), we get
34 + d = 51
∴ d = 17
Now adding Eqs. (i), (ii), (v), we get
a + b + c + d + e + f = 33 + 44 + 17 = 94
∴ Average of a, b, c, d, e and f = 94/6 = 15²⁄₃