Critical Reasoning

Last year all refuse collected by Shelbyville city services was incinerated. This incineration generated a large quantity of residual ash. In order to reduce the amount of residual ash Shelbyville generates this year to half of last year's total, the city has revamped its collection program. This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year's numbers.

WHICH OF THE FOLLOWING IS REQUIRED FOR THE REVAMPED COLLECTION PROGRAM TO ACHIEVE ITS AIM?

A) This year, no materials that city services could separate for recycling will be incinerated.
B) Separating recyclable materials from materials to be incinerated will cost Shelbyville less than half what it cost last year to dispose of the residual ash.
C) Refuse collected by city services will contain a larger proportion of recyclable materials this year than it did last year.
D) The refuse incinerated this year will generate no more residual ash per truckload incinerated than did the refuse incinerated last year.
E) The total quantity of refuse collected by Shelbyville city services this year will be no greater than that collected last year.

IMO: A
OA: D

Premise 1: Last year (e.g. 2010), all refuse collected in S City was incinerated. Incineration generated a large qty of ash.
Premise 2: S City will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year's number.
Concl: S City will reduce the ash total by half.

If S City starts incinerating it's recyclable items, then the ash count won't decrease. The whole point of S City wanting to separate RECYCLABLES vs. NORMAL REFUSE is because they didn't do this last year ("...all refuse collected was incinerated"). Therefore, this program is trying to decrease the number of refuse that goes into the burner. If they start burning recyclable materials, than the argument completely falls apart and so does the city's plan. No?

For D, is it okay even if the statement doesn't even talk about the recycling program?

This question was discussed previously, but I thought I might get more clarity on why my initial answer is false. https://www.beatthegmat.com/having-tough ... 58377.html[/spoiler]

Option D is obvious, as otherwise even if half truckload are sent and per truckload residual ash is twice then ash collected will be same as prev year, so residual ash per truckload shoudn't be more than last year as precisel D tells.

A is not a must, take for example, some of the separated material is incarcated and results in some residual ash, if that amount is compensated by decrease per truckload to be incarcated, overall goal is met.

A says no refuse that could be recould be recycled will be incinerated
Consider the scenario when the entire load is recyclable but the author suggests that we just seperate material enough so that the remainder when incinerated leaves only half the amount of residual Ash left last year