Mr. Gibbs bought number of shirts for the new members of his band. The cost for number of shirts, including $3.99 shipping, was $77.49. Each shirt cost $12.25. There was no sales tax on this purchase. How many shirts did Mr. Gibbs buy?

Number of shirts= 6

Step-by-step explanation:

Giving the following information:

The cost for several shirts, including $3.99 shipping, was $77.49. Each shirt cost $12.25.

First, we need to calculate the net total price paid  for the shirts:

Net total cost= 77.49 - 3.99= $73.5

Now, the number of shirts bought:

Number of shirts= 73.5 / 12.25

Number of shirts= 6

(n^3 - n)

= n(n-1)(n+1)

since it is divisible by 3 and 2 ,because it is a multiple 3 consecutive number

if, n-1 is odd then n+1 is also odd, then it is a multiple of 9

but if, n-1 is even then n+1 is also even, then it is a multiple of 4

so, largest multiple = max(9*2, 4*3) = max(18, 12) = 18