Question

The value of n, when np₂ = 20 is: 

(a) 3 

(b) 6 

(c) 5 

(d) 4

Answer 1

(c) 5

nP₂ = 20 

n(n – 1) = 20 

n(n – 1) = 5 x 4 

∴ n = 5