Critical Reasoning

Shipping Clerk: The five specially ordered shipments sent out last week were sent out on Thursday. Last week, all of the shipments that were sent out on Friday consisted entirely of building supplies, and the shipping department then closed for the weekend. Four shipments were sent to Truax Construction last week, only three of which consisted of building supplies.

If the shipping clerk's statements are true, which of the following must also be true?

A. At least one of the shipments sent to Truax Construction last week was specially ordered.
B. At least one of last week's specially ordered shipments did not consist of building supplies.
C. At least one of the shipments sent to Truax Construction was not sent out on Thursday of last week.
D. At least one of the shipments that were sent out on Friday of last week was sent to Truax Construction.
E. At least one of the shipments sent to Truax Construction last week was sent out before Friday.

[spoiler]OA: E[/spoiler]

I was between A and E.

How to choose between A and E?

Thanks.

Shipping Clerk: The five specially ordered shipments sent out last week were sent out on Thursday. Last week, all of the shipments that were sent out on Friday consisted entirely of building supplies, and the shipping department then closed for the weekend. Four shipments were sent to Truax Construction last week, only three of which consisted of building supplies.

If the shipping clerk's statements are true, which of the following must also be true?

A. At least one of the shipments sent to Truax Construction last week was specially ordered.
B. At least one of last week's specially ordered shipments did not consist of building supplies.
C. At least one of the shipments sent to Truax Construction was not sent out on Thursday of last week.
D. At least one of the shipments that were sent out on Friday of last week was sent to Truax Construction.
E. At least one of the shipments sent to Truax Construction last week was sent out before Friday.

From the red highlighted parts, we know that Truax got 4 shipments last week, and 3 of those were building supplies. We also know that all shipments made friday were building supplies. This means the remaining one shipment was made on a day other than Friday. Since we know the shipping dept was closed on the weekend, the 4th shipment must have been made before friday. Hence, E.

In A, you are assuming that the 4th shipment was specially ordered. It might have been, but we cant say that for sure unless we were given that building supplies' shipments were made ONLY on friday.

Hi,

See if my explanation on a parallel post helps: https://www.beatthegmat.com/post262563.html#262563

Cheers

Thanks guys.