A jar contains 100 marbles. 3/5 of the marbles are black. What fraction of the marbles are black, using 100 as the denominator?

3/5 are black. To rewrite the fraction with a denominator of 100. Find how many thieves the denominator 5 goes into 100:

100/5 = 20

Multiply both the numerator and denominator by 20:

3/5 = 60/100

(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