­Accountant: We need the new sewing machines for the jacket contract

­Accountant: We need the new sewing machines for the jacket contract, which will not be finished in time for us to make dress shirts unless we start the jackets next week. To install the machines this week, we must pay workers overtime—for which there is no money.

Executive: We can contract for sweatshirts instead of dress shirts. The contract will be as profitable but can be started two weeks later—that way we can avoid any overtime work.

The executive has concluded that they can avoid overtime work by contracting for sweatshirts instead of dress shirts because the sweatshirt contract can be started two weeks later.

Given what the accountant says about finishing the jacket contract in time for making dress shirts, we can see that reason the executive's plan could work is that it would allow the jacket contract to be started later than it would have to be if they contracted for dress shirts. Thus, switching to sweatshirts would serve to eliminate the need for paying workers overtime to install the machines "this week."

If the sweatshirt contract can be started two weeks later, then presumably, the jacket contract can be started two weeks later, in which case they will have two additional weeks to install the machines.

For the executive’s plan to succeed in avoiding the need for overtime, which of the following must be true?

Since the correct answer must state something that must be true for the plan to succeed, this question is a type of Assumption question. So, we can handle it as an Assumption question and look for a choice such that, if it's not true, the plan won't succeed.

A. Workers who sew jackets and shirts will know how to install industrial sewing machines.

This choice does not have to be true for the plan to succeed since they didn't say that they would rely on the workers who sew to install the machines.

Eliminate.

B. The new sewing machines can be installed by the end of next week without overtime work.

This choice does not have to be true for the plan to succeed.

The accountant mentions installing new sewing machines "this week."

Then, as discussed above, the executive says that, by contracting for sweatshirts instead of dress shirts, they can start to make shirts "two weeks later."

"Two weeks later" than "this week" is not "next week." Rather, two weeks later than this week is the week after next week.

So, the executive's plan does not involve installing the new machines "by the end of next week." It involves installing them by the week after next week.

Thus, the plan can work even if it's NOT true that the new machines can be installed by the end of next week without overtime work. 

Eliminate.

C. If the new sewing machines are installed without overtime work, the jacket contract can be completed on time without overtime work.

This choice is tricky because we could get the impression that, since they don't mention overtime in discussing the contracts, they're not concerned with overtime involved in completing the contracts.

At the same time, none of the other choices work. So, this is the only possible answer.

So, we can go back to the passage to confirm that they don't say anything about the jacket contract that indicates that this choice doesn't have to be true for the plan to succeed.

Doing so, we that the accountant says the following about the jacket contract:

We need the new sewing machines for the jacket contract, which will not be finished in time for us to make dress shirts unless we start the jackets next week.

Meanwhile, the executive says nothing about the jacket contract.

Thus, when the executive says, "that way we can avoid any overtime work," the executive must be assuming that the contracts, including the jacket contract, can be completed without any overtime work. After all, if this choice is not true, then even if the machines are installed without overtime work, they'll still end up with overtime work.

So, we can see that, for the plan to succeed, it must be true that the jacket contract can be completed on time without any overtime work.

Keep.

D. Workers can sew sweatshirts faster on the new machines than on the old ones.

This choice doesn't have to be true for the plan to succeed since the way the plan succeeds is by pushing back when they need to start working on shirts, not by having the workers sew faster.

Eliminate.

E. A sweatshirt does not take longer to sew than a dress shirt.

The executive states as fact that the sweatshirt contract can be started two weeks later. In doing so, the executive must be taking into account how long it takes to make a sweatshirt. So, there's no reason to believe that it must be true that a sweatshirt does not take longer to sew because, even if it does, the sweatshirt contract can be started later, apparently.

Eliminate.

Correct answer: C­