Question

find the value of n if 2nc3 : nc2 = 12:1​

Answer 1

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 2

Answer:

12:1 point 13:2, 19:6, 75:7,