find the value of n if 2nc3 : nc2 = 12:1
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find the value of n if 2nc3 : nc2 = 12:1
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Step-by-step explanation:
ANSWER
We have,
2n
C
3
:
n
C
3
=12:1
⇒
n
C
3
2n
C
3
=
1
12
⇒
(2n−3)!3!
2n!
.
n!
(n−3)!3!
=12
⇒
(2n−3)!n!
2!(n−3)!
=12
⇒
6
2n(2n−1)(2n−2)
×
n(n−1)(n−2)
6
=12
⇒
(n−2)
4(2n−1)
=12
⇒2n−4=12n−24
⇒4n=20
∴n=5
Hence, this is the answer
Answer:
12:1 point 13:2, 19:6, 75:7,