im assuming its just a regular number cube with 6 numbers
there are only 2 odd numbers above 1 ( 3 and 5)
so the ratio is 2/6
you want to know how manny times (x) will you roll those numbers out of 78 roll
the ratio is x/78
multiply
(2/6) = (x/78)
cross multply to give you 6x= 156 and divide by 6
to give you x = 26
