Copper wire magnetic force help

[qazxcdew11]

Question Details:
In the figure the top wire is 1.1 -diameter copper wire and is suspended in air due to the two magnetic forces from the bottom two wires. The current is 50 in each of the two bottom wires.

Calculate the required current flow in the suspended wire.
i have been working on it for a long t,me.if one who knows a solution appear, i will be happy

 

[Doc Al]

Show what you've done so far and where you are getting stuck.