Question

ram reads one fifth pages of book.if he reads further 40 pages, he would have to read seventh tenth pages of the book. find out the total number of pages in book?

Answer 1

Let the total number of pages in the book be 'y'.

No. of pages read by Ram ⇒ $\sf \frac{1}{5} \ of \ y$

If he reads 40 pages more then, he would have read $\sf (\frac{7}{10})th$ pages of the book.

Now let's solve keeping those in mind.

$\sf (\frac{1}{5}\times y )+40 = \frac{7}{10} \times y$

$\sf (y+200) \div 5 = \frac{7y}{10}$

Now we have to cross multiply.

$\sf 2y+400=7y$

$\sf 400 = 7y-2y$

$\sf 400 = 5y$

$\sf 5y = 400$

$\sf y = \frac{400}{5}$

$\sf y=80$

Pages read by Ram ⇒ $\sf Total \ pages - Pages\ read$

$\sf y-(\frac{7y}{10})=(\frac{3y}{10})$

$\sf \frac{3}{10} \times 80$

$\sf 3\times 8$

$\sf 24$

∴ The total number of pages in the book is 24.