Question

a book seller makes a profit of 20% by selling a book for rs.72.find the cost hi of the book.

Answer 1

72×100/120=7200/120 =720/12=60
cost of the book is 60

Answer 2

Answer:

$sp = \: cp(1 \times \frac{gain}{100} ) \\ 72( \frac{120}{100}) = 60$