TS EAMCET 2017 Code A Solved Paper

In the expansion of (1+x)n, the general term that is, (r+1) th term is,
Tr+1=nCr(1)n−1xr
=nCrxr
The coefficient of pth term is
P=nCp−1
P=‌‌

n!

(p−1)(n−p+1)

....(1)
The coefficient of (p+1) th term is,
q=nCp.....(2)
Divide equation (1) by (2)
‌‌

p

q

=‌‌

‌‌ n! (p−1)(n−p+1)

nCp

‌‌

p

q

=‌‌

p(p−1)(n−p)!

(n−p+1)(n−p)!(p−1)!

‌‌

1

q

=‌‌

1

n−p+1

p+q=n+1