1 ) there are 10 teams in a league .if each team is to play evcry other team exactly once .

A ) how many games must be scheduled ?

B ) How many games must be on each team ?

A ) 10C9 = 10

B ) 10C1 = 10

2 )_A catering service offers 8 appetize, 10 main courses and 7 desserts . A Chairperson is to select

3 appertizs , 4 main courses and 2 desserts for A dinner . How many way can this be done ?

Here in this question we use C or P and why ?