11

In the quinary (base-5) numeral system, the number 11 represents eleven fives, which is equivalent to 6 in the decimal (base-10) numeral system. The quinary system uses five digits: 0, 1, 2, 3, and 4. Each successive digit in this system has a value five times greater than the previous one. Thus, the first digit represents the number of units, the second digit represents the number of fives, the third digit represents the number of twenty-fives (5 squared), the fourth digit represents the number of one hundred and twenty-fives (5 cubed), and so on.