Answer:
a. 475.14 Hz
b. 1959 Hz
c. 2341.53 Hz , 3053.34 Hz
Step-by-step explanation:

a. smallest use the capacitive 4.2 uF + 6.0 uF = 10.2uF replacing:


b. second smallest use the capacitive 6 uF so:


c. second largest and largest oscillation first combination so:
Use 4.2 uF


And finally largest oscillation cap in serie so:



