Kim's team needs 18 points to win. 18-6=12. Four more innings to go 12/4=3. Kim's team needs a minimum average of 3 runs for each of the next 4 innings to win the game.
To evaluate the combination we proceed as follows: 21C3 Given nCk we shall have: n!/[(n-k)!k!] thus plugging the values in the expression we get: 21!/[(21-3)!3!] =21!/(18!×3!) =1330 Answer: 1330
