A Hard Grade 5 Math Question For Adults Supposedly

Hi there. I came across this hard Grade 5 math question that left adults confused. I want to check this question out (even though I knew it was clickbaity).

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The Question

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This math question was intended for grade 5 students. It was shared on Reddit. Here it is.

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Question 12
Klein read 30 pages of a book on Monday and 1/8 of the book on Tuesday.

He completed the remaining 1/4 of the book on Wednesday. How many pages are there in the book?

 

Klein does read the book over these 3 days even though it is not clearly stated.

Solution

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Start by thinking that the book represents one whole. The information given for Monday is 30 pages. For Tuesday we know that Klein read one eight of the book. Wednesday's reading is one quarter. Set up the equation as follows.

? + 1/8 + 1/4 = 1

We want to determine the fraction of the book read for Monday. This Monday fraction also represents 30 pages. Convert one quarter 1/4 into 2/8. Then you have

? + 1/8 + 2/8 = 1

As Tuesday and Wednesday make up 3/8th of the book's reading. This would mean that Monday would be five eighths of the book.

This five eighths (5/8) represents 30 pages. One eighth would be 30 divided by 5 which is 6 pages.

We want the whole book which is 8 eights. This is 6 pages times 8 or 48 pages.

 

Pictures Approach To Solution

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Pictures in the form of fraction circles can be used too. I use webwhiteboard.com for the visuals. Sorry if its uneven!

A pictures approach to the word problem helps with visualizing the parts and the whole. This solution is a bit easier for those not familiar with equivalent fractions and lowest common denominators.

Monday takes five pieces out of eight. These five pieces represent 30 pages. One piece or one eighth is 6 pages. The book represents all 8 pieces of the fraction. Doing 6 pages times 8 also gives the answer of 48 pages for the whole book.

 

Notes

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This particular math problem is listed as grade 5. Grade 5 from where I wonder? I don't think this question is that easy. I also don't think this is impossible. Many adults do tend to forget their math over the years. This is because a lot of math is not really used. Due to forgetting stuff elementary grade school questions like this can seem confusing regardless of subject.

I don't think that it is the end of the world if a grown up is not able to answer this. You can still be successful and rich without knowing fractions.

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Thank you for reading.