Question

a book seller buys a number of books for rupees 1760.If he bought 4 more books each book have cost rupees 22 less how many books did he bought

Answer 1

16×110=1760
20×88=1760
the cist difference is 22.
the Number of book difference is 4
so the original purchase was 16 books

Answer 2

$\Large{\textbf{\underline{\underline{According\;to\;the\;Question}}}}$

Assumption,

Bookseller bought p books

Cost of books = 1760/p

Also,

Cost of p + 4 books :-

= 1760/p + 4

Situation,

1760/p - 1760/p + 4 = 22

1/p - 1/p + 4 = 22/1760

(p + 4) - p/p(p + 4) = 1/80

4/(p² + 4p) = 1/80

p² + 4p = 320

p² + 4p - 320 = 0

p² + 20p - 16p - 320 = 0

p(p + 20) - 16(p + 20) = 0

(p + 20)(p - 16) = 0

p + 20 = 0 or p - 16 = 0

p = - 20, 16 (Negative value is not applicable)

p = 16

Therefore,

Bookseller bought 16 books