Question

A book – seller has 100 books in his shop. He sells 3 for Rs. 27 each. What is the cost of 1 book? How much will he earn after selling all his 50 books? What will be the cost of 100 books?

Answer 1

Hint: We will firstly calculate the cost of one book.Then we will calculate the cost of 50 books.We will find the cost of 50 books by multiplying the cost of one book with 50. Then, we will find the cost of 100 books by multiplying the cost of one book with 100.

Complete step-by-step answer:
Let us solve this question now.
Cost of 3 books = Rs. 27
Cost of one book = \[\dfrac{27}{3}\]
                                   = 9
Therefore, the cost of one book is Rs. 9.
So, let us now calculate the cost of 50 books.
We will multiply the cost of 1 book by 50.
Cost of one book = Rs. 9
Cost of 50 books = \[50\times 9\]
                                   = 450
So, the cost of 50 books is Rs. 450.
Let us now find the cost of 100 books.
We will multiply the cost of 1 book by 100.
Cost of one book = Rs. 9
Cost of 100 books = \[100\times 9\]
                                 = 900
So, the cost of 100 books is Rs. 900.

NOTE: One must do all the calculations very carefully for solving this question.
Also, not only in this question, one must be very careful while doing such questions as any mistake in the calculus can make the answer wrong.