Official solution
Total no of trials = 5
\[\therefore\] n = 5
Odd no possibe are = {1, 3, 5} =3
Sample space = {1, 2, 3, 4, 5, 6} = 6
Probablity of getting odd number = \[{3 \over 6}\] = \[{1 \over 2}\]
\[\therefore\] p = \[{1 \over 2}\]
Formula for variance = npq
where q = 1 - p = 1 - \[{1 \over 2}\] = \[{1 \over 2}\]
\[\therefore\] Variance = \[5 \times {1 \over 2} \times {1 \over 2}\] = \[{5 \over 4}\]