UPSEE Solved Model Paper 3

Total number of m elements subsets of A =

n

‌

Cm and number of m elements subsets of A each containing the element a4 =

n−1

‌

Cm−1
According to question,

n

‌

Cm = λ.

n−1

‌

Cm−1
⇒

n

m

.

n−1

‌

Cm−1 = λn−1Cm−1
⇒ λ =

n

m

⇒ n = mλ