What is the minimum input current I for which the transistor will begin to turn on?

I dont understand why the answer is the same as the current through the 47k resistor (I = 1.489µA). Wouldnt the answer be different, since the current at the junction spilts? (some goes to the base and rest through the resistor?)

 

For the second transistor to begin to turn on the first transistor must start conducting. The spec wouldn't change since the second transistor is entirely dependent on the first.