To start do you know how to solve for BJT circuits?
The goal of this forum is to share knowledge and grow the community and members, not to just blindly give you answers. In order to properly help you learn we need to know what level of experience you have, and why you are stuck on a problem. We won't spoon feed you answers if you don't respond to our questions.why you make it so difficult?????
it easy, i put the problem in other forum
this is the answer for there
The base-emitter voltage of the 2N5401 Q6 is about 0.62V when it begins to turn on. When Q6 turns on it begins to cutoff Q7 so the current in R9 and Q7 is constant at 0.62V/62 ohms= 10mA.