Official Solution:
A survey of office managers who had acquired new printing equipment over the previous five years found that twelve percent of laser printers in use had needed servicing on more than one occasion, compared with just three percent of inkjet printers that had ever required any servicing at all. Offices that depend on uninterrupted access to printing should therefore expect far fewer workflow disruptions by choosing inkjet over laser printers.
Which of the following is an assumption the argument relies on?
A. Inkjet printers do not produce noticeably lower print quality than laser printers for standard office documents.
B. Offices that use laser printers are not far more likely to operate them at substantially higher print volumes over time than offices that use inkjet printers.
C. At least as many offices in the survey had acquired laser printers as had acquired inkjet printers.
D. Laser printers do not generally require longer periods of downtime for each service visit than inkjet printers do.
E. Offices that acquired printing equipment within the past year are not far more likely to have chosen laser printers than offices that acquired equipment five years ago.
The argument concludes that offices wanting uninterrupted printing access will face fewer workflow disruptions by choosing inkjet over laser printers, based on survey data showing twelve percent of laser printers needed servicing more than once compared with just three percent of inkjet printers ever requiring service. The gap is that the survey covers all offices, and if offices with laser printers consistently operate them at far higher print volumes, the higher servicing rate might reflect heavier use rather than lower reliability.
(A) Incorrect. The conclusion concerns how often printers require servicing, not the quality of their output. Whether inkjet printers produce lower print quality has no bearing on how frequently either type breaks down.
(B) Correct. If offices with laser printers consistently operate them at substantially higher print volumes, the higher servicing rate could simply reflect greater wear from heavier use rather than any inherent difference in reliability. A laser printer used at the same volume as an inkjet might break down no more often. Negating this answer means the repair rate difference no longer supports the conclusion.
(C) Incorrect. The evidence is expressed as percentages of each printer type. The relative number of each type acquired has no bearing on what those percentages imply about reliability.
(D) Incorrect. This goes in the wrong direction. If laser printers require longer downtime per service visit, offices using them face disruptions that are both more frequent and longer-lasting - which only strengthens the conclusion. The argument does not depend on this.
(E) Incorrect. If businesses have purchased quite a few laser printers in the past year that can skew the composition of the printers being evaluated towards a newer fleet of laser printers vs. older ink jets, so this can skew the statistics. However, the laser printers already are under-performing even while they are much newer per this scenario; thus this is not an assumption we need to rely upon. The opposite assumption (that the ink jet printers are not much newer would be true, but that's not present in the options).
Answer: B