# A Book contains 100 pages . a page is chosen at random. what is the chance that the sum of the digits on the page is equal to 9?

We know Probability P ( E ) = $\frac{Totalnumberofdesiredeventsn(E\hspace{0.17em})}{Totalnumberofeventsn(S\hspace{0.17em})}$

Here we have book contains 100 pages .

So,

Total number of events n ( S ) = 100

And

Pages that have sum of the digits on the page is equal to 9 = { 9 , 18 , 27 , 36 , 45 , 54 , 63 , 72 , 81 , 90 }

So,

Total number of desired events n ( E ) = 10

So,

Probability of getting sum of the digits on the page is equal to 9, P ( E ) = $\frac{10}{100}=\frac{\mathbf{1}}{\mathbf{10}}\mathbf{(}\mathbf{}\mathit{A}\mathit{n}\mathit{s}\mathbf{}\mathbf{)}$

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