Explain me this situation

A spider is attached to two threads of equal length that make a 120o angle with each other. The spider is motionless and its mass is m=30mg.

What is the tension in each thread?

According to the Newton first Law, the sum of the force must be 0.

T1+T2+Fspider=0

since the threads are the same length and symetrical, T1=T2.

Fspider=-3.0 *10-4N

so I found T1=1.5 *10-4N

I am surprised to see that the answer is 3.0 *10-4N on each thread

please now I am confused! help