Need help

[Madu]

The price of a text book is Rs 200 more than the price of five 80 page books. If the price of the text book is Rs400 , what is the price of an 80 page exercise book? How to get the answer for this?

 

[Otis]

Hi Madu. I would begin by picking a symbol to represent what they've asked for.

Let x = the price of one 80-page book

… the price of five 80 page books …

Using symbol x, we express the amount for five 80-page books as 5x.

200 more than that amount is expressed as 5x+200.

If you'd like more help, please follow the forum's guidelines and show your work. Cheers.

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[HallsofIvy]

If you don't want to use algebra, writing "x" for the cost of the "five eighty page books", you a can argue this way:

To "undo" a calculation, you do the opposite- the opposite of "add 200" is "subtract 200" and the opposite of "multiply by five" is "divide by five".

A text book cost 400 Rs and that is "200 Rs more than five eighty page books". "200 more" means 200 has been added so the five eighty page books cost 400- 200= 200 Rs.

Since the five eighty page books costs 200Rs, a single eighty page book cost 200/5= 40 Rs.

 

[Madu]

Thank you so much for the answer. I got the same answer but I was confused, because It says, "more than the price of five 80 page books" not exactly five 80 page books. That's why

 

[Otis]

… I got the same answer but …

Hi Madu. Next time you'd like your answer checked, please include it with your work when you post.

I was confused, because It says, "more than the price of five 80 page books" not exactly five 80 page books.

Ah. In that case, the English would have been, "the price of more than five 80-page books", and we wouldn't have been able to solve it. (I can't think of an example where the phrase "more than" does not apply to a noun immediately following it.)

Maybe it would be clearer worded like this (using Indian rupee):

A ₹400 textbook costs ₹200 more than a set of five 80-page books.

400 = 200 + 5x

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[Madu]

Thanks, I got it