Question

Penn stacks all his snowballs in a square pyramid. the number of snowball, P(n) in n layers of the square pyramid is given by P(n)= P(n-1) +n2

which could not be the number of snowballs Penn has?

A: 5

B: 30

C: 25

D: 14

Answer 1

Right answer is C-25
P(1)=1
P(2)=P(2-1)+2^2=1+4=5
P(3)=P(3-1)+3^2=5+9=14
P(4)=P(4-1)+4^2=14+16=30
There isn’t 25

Answer 2

C: 25

Explanation:

P(n)= P(n-1) +n²

P₁ = P₀ + 1² = 0 + 1 = 1

P₂ = P₁ + 2² = 1 + 4 = 5 (Option A)

P₃ = P₂ + 3² = 5 + 9 = 14 (Option D)

P₄ = P₃ + 4² = 14 + 16 = 30 (Option B)

The number of snowballs cannot be 25.