Percentage Questions Tricks Part 7th

Let’s continue with this chapter............

Concept 6^th   :- (Miscellaneous Questions based concept.)

Q24. In a library 20% of the books are in Hindi, 50% of the remaining books are in English and 30% of the remaining books are in French. Remaining 6300 books are in regional language. Find the total number of books in the library.

Note:- In such type of questions you should analyse the question very carefully and then you can solve this question by following two methods.

Sol. 1^st Method :- Let the total number of books in the library be 100.

20% of these books are in Hindi = 20 books in Hindi.

Therefore the remaining books = 100 – 20 = 80 books.

50% of these remaining books are in English = 50% of 80 = 40 books.

Therefore the remaining books = 80 – 40 = 40 books.

30% of these remaining books are in French = 30% of 40 = 12 books.

Now the remaining books = 40 – 12 = 28 books.

According to the question the total remaining books = 6300.

On applying Unitary Method:-

When remaining books are 28 then total books in library = 100.

Again when remaining book is 1 then total books in the library will be = (100/28)

Therefore when remaining books are 6300 then the total books in the library

= (100/28) × 6300

= 22,500 books

Hence the total number of books in the library = 22,500 books.

2^nd Method:- In these type of Question we can use the direct method of one line calculation.

Let the total number of books in the library = x

According to the question:-

20% of the books in Hindi.

50% of the remaining books in English.

30% of the remaining books in French.

Total remaining books = 6300.

Now applying trick we get

x × {(100 - 20)/100} × {(100 – 50)/100} × {(100 – 30)/100} = 6300

x × (80/100) × (50/100) × (70/100) = 6300.

x = {(6300 × 100 × 100 × 100)/(80 × 70 × 50)

On solving we get

x = 22,500

Hence the total number of books in the library = 22,500 books.

Q25. The manufacturer of an article makes a profit of 25%, the whole-seller makes a profit of 20% on the same article and the retailer makes a profit of 28% on the same article. Find the manufacturing price of the article if the retailer of the article sales it at Rs. 48/-.

Sol. Analyse the given data :-

Let the manufacturing price of the article be x.

The manufacturer makes a profit on the article = 25%.

So, the cost price of the article for the whole-seller = x × {(100 + 25)/100}.

Now the whole-seller makes a profit on the article = 20%

So, the cost price of the article for the retailer = x × (125/100) × {(100 + 20)/100}.

Now the retailer makes a profit on the article = 28%.

So, the selling price of the article for the retailer

 = x × (125/100) × (120/100) × {(100 + 28)/100}.

According to the question, the retailer sales the article for Rs. 48/-. Therefore,

48 = x × (125/100) × (120/100) × (128/100).

x = (48 × 100 × 100 × 100)/(125 × 120 × 128)

On solving we get,

x = Rs. 25/-.

Hence the required manufacturing cost of the article = Rs. 25/-

 (Note you may say that this is so long but dear this is the only way to explain the whole concept of the question to you now its upto you that how fast and short handedly you can solve these type of questions)

Hope you have enjoyed the base concept of this chapter till now. More Conceptual enjoyment will be continued for you soon, just keep visiting this blog regularly and writing me your related queries through comment or forum.

More types of questions will be followed soon on this blog........................