Question: In a library 20% books are English, 50% of remaining are French and 30% of remaining are Latin. The rest 6300 are in regional languages. What's the total no. of books?
Answer: Let total books = x
Then no. of books in English= 20% of x= x/5
French = 2x/5
Latin = 3x/25
Another shortcut to solve this question using percentages is given as follows:
I dont understand this shortcut. The Formulae that i've been given are:
To calculate % increase or decrease:
actual increase/original amount*100%
actual decrease/original amount*100%
If the price of something is increased by R%, then reduction in consumption so as not to increase the expenditure /OR/ If A is R% more then B, then B is less than A by:
And the reverse of the above:
The part that i'm confused about in Shortcut solution is the application of the formulae.
IF "(100/100-20) (100/100-50) (100/100-30)" Is derived by applying one of the formula, then HOW has it been done? What is "100"?
If you want to calculate total number of books you have to calculate percentages of percentages:
Originally Posted by Bish4n
Let x denote the total number of books then the number of non-English, non-French and non-Latin books can be calculated as:
Now solve for x and you'll get the given formula.