Kelly has 2 times as many quarters as dimes. She has 18 quarters. How many dimes does she have?

9 dimes

Step-by-step explanation:

If she had 18 quarters, that is 2 times the amount of the dimes, that means that if you divide 18 by 2 you would get 9 dimes. Hope this helps:)

(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