The answer is 32.5%
and if you need it in decimal form, it would be,

This means that everybody answered the same number of items. This means that every data value is equal to the mean. This outcome permits us to say that the sample standard deviation of a data set is zero if and only if all of its values are same or identical.
The sample space is:
(1, 1); (1, 2) - sum of 3; (1, 3); (1, 4); (1, 5) - sum of 6; (1, 6);
(2, 1) - sum of 3; (2, 2); (2, 3); (2, 4) - sum of 6; (2, 5); (2, 6);
(3, 1); (3, 2); (3, 3) - sum of 6; (3, 4); (3, 5); (3, 6) - sum of 9;
(4, 1); (4, 2) - sum of 6; (4, 3); (4, 4); (4, 5) - sum of 9; (4, 6);
(5, 1) - sum of 6; (5, 2); (5, 3); (5, 4) - sum of 9; (5, 5); (5, 6);
(6, 1): (6, 2); (6, 3) - sum of 9; (6, 4); (6, 5); (6, 6)
Answer: 2,550,3066,090,2305,000,9124,340,6001,700,09019,034,004
Step-by-step explanation: I hope it helped