Video solution from Quant Reasoning:

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Since Shawama can read upto 50 pages in a day, and doesn't read the next book on the same day,
once she has finished reading a book on that day.

She will read the following books for the following days.
Book1 - 253 pages will take 6 days
Book2 - 110 pages will take 3 days - (Total: 9 days)
Book3 - 117 pages will take 3 days - (Total: 12 days)
Book4 - 170 pages will take 4 days - (Total: 16 days)
Book5 - 155 pages will take 4 days - (Total: 20 days)
Book6 - 50 pages will take 1 days - (Total: 21 days)
Book7 - 205 pages will take 5 days - (Total: 26 days)
Book8 - 70 pages will take 2 days - (Total: 28 days)

Hence, she would have read 8 books in total at the completion of the 28th day(Option B)
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Shawana reads 50 pages per day. Exception will be that she will never begin the next book on the same day that she finishes the previous one.

Book 1 = 253 pages = 253/50 = 5 days and 3 pages left. Total of 6 days. (------ 6 days)

Book 2 = 110 pages = 110/50 = 2 days and 10 pages left. Total of 3 days. (------- 6 + 3 = 9 days)

Book 3 = 117 pages = 117/50 = 2 days and 17 pages left. Total of 3 days. ( -------- 9 + 3 = 12 days)

Book 4 = 170 pages = 170/50 = 3 days and 20 pages left. Total of 4 days. (------------ 12 + 4 = 16 days)

Book 5 = 155 pages = 155/50 = 3 days and 5 pages left. Total of 4 days. (----------- 16 + 4 = 20 days)

Book 6 = 50 pages = 50/50 = 1 day and 0 pages left. Total of 1 day. (------------- 20 + 1 = 21 days)

Book 7 = 205 pages = 205/50 = 4 days and 5 pages left. Total of 5 days. (------------ 21 + 5 = 26 days)

Book 8 = 70 pages = 70/50 = 1 day and 20 pages left. Total of 2 days. (--------------- 26 + 2 = 28 days)

Therefore she can read total of 8 books in 28 days. Answer (B)...

If she finishes the 6th book on the 21st day, how can she start another one that day when Q stem said she can never start another book the same day.. ? please explain...
If I continue to start the 7th book on 22nd day the result will be A.

Thanks for help!

Hi AnnKatrin,

She finishes the 6th book on the 21st day.

Then, she starts the 7th book on the 22nd day, and reads 50 pages on the 22nd day.
She will read till the 100th page on the 23rd day
,she will read till the 150th page on the 24rth day
,she will read till the 200th page on the 25th day
,and she will read the remaining 5 pages(from 201 to 205) on the 26th day.

Now she starts the 8th book on the 27th day, 50 pages on day 27
and 20 remaining pages of the 70 page book on day 28.

Hence, she would have finished 8 books on the 28th day

Hope that helps you!
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We will list the number of days it will take to read each book. Since Shawana does not start a new book the same day she finishes a book, the number of days for her to read a book will be one more than the number of pages of the book divided by 50 (ignoring remainders).

Book 1: 6 days
Book 2: 3 days (Total: 9 days)
Book 3: 3 days (Total: 12 days)
Book 4: 4 days (Total: 16 days)
Book 5: 4 days (Total: 20 days)
Book 6: 1 day (Total: 21 days)
Book 7: 5 days (Total: 26 days)
Book 8: 2 days (Total: 28 days)

So, in 28 days, Shawana will have finished 8 books.

Answer: B
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Bunuel gmatbusters niks18
pushpitkc

I CAN NOT simply multiply 50* 28 in spite of highlighted text because of portion in RED.
Is my understanding correct?
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Absolutely adkikani

That's what the highlighted portion is implying. In other words, it is not possible to read 2 books on a single day.
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Is there any other method to solve this quest as this technique is taking minimum 2.5 mins

You are the lucky one. It took for me 3.17 to solve the question. On GMAT you will find that some questions take less or more than 2 min to solve. And that's OK, because the avarage time will be 2 min. If you master DS questions, they will be a real time saver, leaving some extra time for hard PS questions.

Total pages : 1750

Every day :50 pages ;

So total time it will take : 1750/50 = 35 days.

But she need to finish it in 28 days = So 28 days * 50 pages per day = 1400 pages.

So remaining pages = 1750 -1400= 350 pages.

If we will add the 11th and 12th book = 143+ 207 = 350 pages.

It means for sure he has not read the 11th and 12 book. So not total book in count not 12 its 10 book only.

But if we will calculate for each day
DAY. She can read( 50 pages everyday) + Extra day after reading 50 per day
BOOK 1: 5 + 1
BOOK 2: 2+1
BOOK 3: 2+1
BOOK 4: 3+1
BOOK 5: 3+1
BOOK 6: 1
BOOK 7: 4+1
BOOK 8: 1+1

If we will Toal these days we will get 28days. So Answer till BOOK 8

This is one of the rare cases when the question prompt is too lengthy and there is some redundant information given in the question.

One needs to notice how days are counted. What does this part mean exactly - The only exception will be that she will never begin the next book on the same day that she finishes the previous one, and therefore on some days she may read fewer than 50 pages.? If a book has 1 or 49 pages, then she will spend 1 day reading this book. Similarly, if the book has 101 or 149 pages, she will spend 3 days. We need to round the number of pages up so that the number of total pages is a multiple of 50, i.e. 101 --> 150 = 50*3.

Now one can go through the rows, round the number of pages, and check how many books Shawana will read when she reaches day 28.

Book 1 - 253 pages --> 300 = 50 * 6 days
Book 2 - 110 pages --> 150 = 50 * 3 days
etc.

She will read 8 books in 28 days, answer (B).

What is the significance of 'Total Pages Read Column'?

They probably provided that as a trap, to get folks to just divide the total number of pages by 50.
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Hi All,

We’re told that Shawana is going to read for 28 days with the following restrictions:

-She will read 50 pages a day from 1 book (or fewer, if doing so would complete that book)
-She will never read from more than 1 book a day.

We’re asked how many total books she will read in the 28-day timeframe.

While this question is really worded (and includes a lengthy table), the math behind it is really just basic Arithmetic – and taking the proper notes should help you to answer this question without too much work. We ultimately need to keep track of how many ‘groups of 50 pages’ each book contains.

Book 1: 253 pages → 5 groups of 50 + 1 group to finish the book = 6 days; total = 6 days
Book 2: 110 pages → 2 groups of 50 + 1 group to finish the book = 3 days; total = 9 days
Book 3: 117 pages → 2 groups of 50 + 1 group to finish the book = 3 days; total = 12 days
Book 4: 170 pages → 3 groups of 50 + 1 group to finish the book = 4 days; total = 16 days
Book 5: 155 pages → 3 groups of 50 + 1 group to finish the book = 4 days; total = 20 days
Book 6: 50 pages → 1 group of 50 = 1 day; total = 21 days
Book 7: 205 pages → 4 groups of 50 + 1 group to finish the book = 5 days; total = 26 days
Book 8: 70 pages → 1 group of 50 + 1 group to finish the book = 2 days; total = 28 days

At this point, we’ve finished the 28th day…

Final Answer:

GMAT Assassins aren’t born, they’re made,
Rich
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Solution:

Given, Shawana reads 50 pages/day, and she will never begin the next book on the same day that she finishes the previous one.

1st book -253 pages= 50*6 =300 --->6 days (As there are 253 pages)

2nd book- 110 pages = 3*50=150---->3 days

3rd book-117 pages=3*50=150------->3 days

4th book-170 pages = 4*50=200------>4 days

5th book-155 pages = 4*50 = 200--->4 days

6th book-50 pages =1*50=50------>1 day

7th book-205 pages=5*50=250----->5 days

8th book-70 pages=2*50=100------->2 days

Total days = 6+3+3+4+4+1+5+2=28 days

=> 8 books would be completed in 28 days(option b)

Devmitra Sen
GMAT SME
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Answer: Option B

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Correct option B

Since Shawama can read upto 50 pages in a day, and doesn't read the next book on the same day,
once she has finished reading a book on that day.

She will read the following books for the following days.
Book1 - 253 pages divide by 50, 5 with Reminder 03 pages = 5+1= 6 days
Book2 - 110 pages divide by 50, 2 with Reminder 10 pages = 2+1= 3 days (Total: 06+3 = 9 days)
Book3 - 117 pages divide by 50, 2 with Reminder 17 pages = 2+1= 3 days (Total: 09+3 = 12 days)
Book4 - 170 pages divide by 50, 3 with Reminder 20 pages = 3+1= 4 days (Total: 12+4 = 16 days)
Book5 - 155 pages divide by 50, 3 with Reminder 05 pages = 3+1= 4 days (Total: 16+4 = 20 days)
Book6 - 050 pages divide by 50, 1 with Reminder 00 pages = 1+0= 1 days (Total: 20+1 = 21 days)
Book7 - 205 pages divide by 50, 4 with Reminder 05 pages = 4+1= 5 days (Total: 21+5 = 26 days)
Book8 - 070 pages divide by 50, 1 with Reminder 20 pages = 1+1= 2 days (Total: 26+2 = 28 days)

Hence, she would have read 8 books in total at the completion of the 28th day(Option B)