swerve wrote: ↑

Thu Dec 14, 2017 11:04 am

Rates for having a manuscript typed at a certain typing service are $5 per page for the first a page is typed and $3 per page each time a page is revised. If a certain manuscrpt has 100 pages, of which 40 were revised only once, 10 were revised twice, and the rest required no revisions, what was the total cost of having the manuscript typed?

A. $430
B. $620
C. $650
D. $680
E. $770

The OA is D.

Please, can any expert explain this PS question for me? I have many difficulties to understand why that is the correct answer. Thanks.

We are given that the manuscript has 100 pages, and, of those pages, 40 were revised once, 10 were revised twice, and the remaining 50 pages had no revisions.

Thus, the charge for the 50 pages that required no revisions was 50 x $5 = $250.

Next, we can determine the total charge for the 40 pages that were revised once. We have an initial charge of $5 per page and an extra charge of $3 per page for the revision. Thus, the total cost was 40 x ($5 + $3) = 40 x $8 = $320.

Finally, we can determine the total cost for the 10 pages that were revised twice. We again have an initial charge of $5 and then a charge of $3 for each revision. Thus, the total cost was 10 x ($5 + $3 + $3) = 10 x $11 = $110.

Therefore, the total cost of all 100 pages is $250 + $320 + $110 = $680.

Answer: D