Answer
Total cost to give all 100 tests: ${$10,000}$
Total averted expenses: ${$15,000}$
Total savings: ${$5,000}$
Work Step by Step
It costs ${$100}$ per test, so to give it to 100 people, it would cost ${$10,000}$.
Suppose 15 people will test positive, the future treatment costs averted $15\times 1,000=15,000$.
With a total cost of ${$10,000}$, and averted expenses of ${$15,000}$, it will save a total of $15,000-10,000={$5,000}$.
