Unless I have misunderstood your question, five sixths out of ninety is the same as 90 minus five sixths. The answer would be 89 and one sixth. But the language is awkward. For example, you may hear in an ad: "seven out of ten parents agree...", which clearly would mean seventy percent of parents. Interpreting the question this way would lead you to think the answer might be something like "5 sixths out of 540 sixths", or roughly .00925. This doesn't strike me as a satisfying interpretation of the question; it would work more with two terms that are both whole numbers. I can only conclude that whether accidentally or by design, the langauge is bad.
dffgffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
Five sixths, as five is greater than two.
Five sixths of 18 would equal 15.
five sixths
It is five sixths.
Five-sixths of sixty is fifty.
33 sixths
10
Five sixths of a yard is 30 inches
1 and five sixths = 1.8333 . . .
Fourteen.
Five sixths is the simplest form.
Five sixths... two thirds equals FOUR sixths.