Let their daily incomes be A, B and C respectively.

Now, A + B = 2 x 350

or,  A + B = 700 - - - - - - - - (i)

Again,  B + C = 2 x 365

or,  B + C = 730 - - - - - - - - - - (ii)

Again,  A + C = 2 x 340

or,  A + C = 680 - - - - - - - - - - (iii)

{(i) + (ii) + (iii)}>>>   A + B + B + C + A + C = 700 + 730 + 680

or,  2(A + B + C) = 2110

or,   A + B + C = 1055

or,  A + 730 = 1055

or,  A = 1055 - 730

or,  A = 325 TK

So, the weekly income of A = 5 x 325 = 1625 TK