Answer :
There is an infinite number of equivalents to 1/81, for example:
2/162 because 1 * 2 = 2 and 81 * 2 = 162
3/243 because 1 * 3 = 3 and 81 * 3 = 243
4/328 because 1 * 4 = 4 and 81 * 4 = 328
2/162 because 1 * 2 = 2 and 81 * 2 = 162
3/243 because 1 * 3 = 3 and 81 * 3 = 243
4/328 because 1 * 4 = 4 and 81 * 4 = 328
