Question

यदि ⁿC₈ = ⁿC₂, तो  ⁿC₂  ज्ञात कीजिए।

Answer 1

ⁿC₈ = ⁿC₂ = ⁿC_n - 2

ⁿC₈ = ⁿC_{n - 2}

8 = n - 2

∴ n = 10

∴ ⁿC₂ = ¹⁰C₂ = `(10!)/(2!(10 - 2)!) = (10!)/(2!8!)` = `(10 xx 9 xx 8!)/(2 xx 1 xx 8!) = 45.`