The transistor Q1 has a current gain \( \beta_1 = 99 \) and the transistor Q2 has a current gain \( \beta_2 = 49 \). The current \( I_{B2} \) in microampere is \(\underline{\hspace{2cm}}\).
All the transistors used in the circuit are matched and have a current gain \( \beta = 20 \). Neglecting the Early effect, the current \( I_{O4} \) in milliamperes is \(\underline{\hspace{2cm}}\).
