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NCERT Exemplar · Class 7 · Maths

Chapter 2: Fractions and Decimals

Practice each question, then open the answer or worked solution.

Questions

61 questions
Q61Written answer

Reemu read (1/5)th pages of a book. If she reads further 40 pages, she would have read (7/10)th pages of the book. How many pages are left to be read?

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Worked solution

Solution:-

From the question it is given that,

Reemu read (1/5)th pages of a book.

Let us assume the total number of pages in the book be ‘P’.

Then, number of pages read by Reemu = (1/5) of P

= (1/5) × P

And also, it is given in the question, If she reads further 40 pages, she would have read (7/10)th pages of the book. = (7/10) × P

So,

((1/5) × P) + 40 = (7/10) × P

(P + 200)/5 = (7P/10)

By cross mutliplication we get,

2P + 400 = 7P

5P = 400

P = 400/5 … [divide both numerator and denominator by 5]

P = 80

Then, pages read by Reemu = Total pages – Pages read

P – (7P/10) = (3P/10)

(3/10) × 80

24 pages

Therefore, 24 pages are left to be read.

NCERT Exemplar Class 7 Maths Solutions Chapter 2 Image 27

Solution:-

Let us assume the missing number be P.

Then,

(3/7) × P = 15/98

By cross multiplication we get,

P = (15/98) × (7/3)

P = (5/14) × (1/1)

P = 5/14

Therefore,

NCERT Exemplar Class 7 Maths Solutions Chapter 2 Image 28