28 cell phone cases in all.
6 of the 28 cases are fabric.
6/28 simplified to 3/14
So the answer to your question would be 3/14
Hope this helps! :)

is the logical or/disjunction symbol.

means "

or

". Disjunction is commutative, which means

is equivalent to

.
So if

represents

and

represents

, then

means

or

.
d1 = 51(t)
d2 = 71(8 - t)
d1 + d2 = 508
and now you just have to solve for t.