Q24 of 30 Page 7

Determine n if   (i) 2nC3: nC2 = 12:1   (ii) 2nC3 : nC3 = 11:1.


(i)=

× =12

= 12

2n-1 = 9

2n = 10

n = 5

(ii) 2nC3 : nC3 = 11:1

=1

= 11

=

4(2n - 1) = 11(n - 2)

8n – 4 = 11n – 22

18 = 3n

n = 6

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