Question

Find n if ⁿC₈ = ⁿC₁₂ 

Answer 1

ⁿC₈ = ⁿC₁₂ 

If ⁿC_x = ⁿC_y, then either x = y or x = n – y

∴ 8 = 12 or 8 = n – 12

But 8 = 12 is not possible

∴ 8 = n – 12

∴ n = 20