Calculate the tension in a tube

[Quantum Fizzics]

Homework Statement

given mass: 100g(the one hanging)
Q1 = -30(mu)C
Q2 = 70(mu)C
Q3 = 50 (mu)C
T=?
Length of tube = 2m
Length of rope = 1m

Homework Equations

Ft + Fg + Felect =0
F =k *q1*q3/d2

The Attempt at a Solution

Those were the equations I have done so far, so the answer is 46N & the answer I got was -45N(ref dir) but I'm not sure if I have done it right here is the diagram : http://gyazo.com/1d33f7708faf12ffea9138b7c2ee6eac
How I did it at first:
Ft (+)Fg(+)Felect(+) = 0
Ft+ 0.1(10) + 9x10^9x70x10^(-6)x50x10^-6/1
FT= -31.5N

F13 = kxq1xq3/d2
= 9x10^9(-30x10^-6)(50x10-6)/1^2
F13= +- 13.5N
then I added them both

 

[SteamKing]

It seems like you have omitted a portion of the problem statement. It's not clear what you are supposed to be doing here. Can you please post the original problem as it appeared in its original form?

 

[Quantum Fizzics]

It seems like you have omitted a portion of the problem statement. It's not clear what you are supposed to be doing here. Can you please post the original problem as it appeared in its original form?

That was the whole question. He just gave us the diagram, & the numbers and told us to calculate the tension.

 

[haruspex]

given mass: 100g(the one hanging)
Q1 = -30(mu)C
Q2 = 70(mu)C
Q3 = 50 (mu)C

That doesn't seem to give a stable arrangement. Shouldn't the negative charge be in the middle?