The answer to your question above would be: 7z-2/z-7
Area of rectangle = 15 x 8
=120
area of parallelogram = 8 x 15
=120
so, they have the same area, because the length of a rectangle is the same as the height of a parallelogram and also for the base.
Given that 4000 items are checked in one month, let the number of detective items be represented as y.
Quality control finds on average that 0.026% of the items in the factory are detective. This implies that

When 4000 items are checked, we have the number of detective items to be evaluated as

Hence, the number of detective items is 1.04.