Answer:
Step-by-step explanation:
Given
There are 120 Pianist in a competition
(a)In first round 30 pianist is selected
this can be done in [tex]^{120}C_{30} ways[/tex]
[tex]=\frac{120!}{(120-30)!30!}[/tex]
[tex]=\frac{120!}{90!30!}[/tex]
(b)In the second round 5 pianist is selected out of 30
this can be doe by [tex]=\frac{30!}{(30-5)!5!}[/tex]
[tex]=\frac{30!}{25!5!}[/tex]
[tex]=142,506[/tex]