4 votes 4 votes 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 $8$? $0.08$ $0.09$ $0.90$ $0.10$ Quantitative Aptitude go-mockgate-1 engineering-mathematics probability quantitative-aptitude + – Ruturaj Mohanty asked Dec 27, 2018 • retagged Sep 10, 2020 by ajaysoni1924 Ruturaj Mohanty 3.2k views answer comment Share Follow See all 5 Comments See all 5 5 Comments reply Show 2 previous comments amanverma== commented Dec 28, 2018 reply Follow Share (1,7)(7,1)(2,6)(6,2)(3,5)(5,3)(4,4) and page number 8 itself are the total possible combinations.Shouldn't answer be 0.08 0 votes 0 votes Magma commented Dec 28, 2018 reply Follow Share Why not 80 and 08 ?? 0 votes 0 votes amanverma== commented Dec 28, 2018 reply Follow Share Ohh....I forgot 80 :) 0 votes 0 votes Please log in or register to add a comment.
Best answer 6 votes 6 votes Note:- single digit page 8 can be written in 2 digit as 08. the sum of two digits should be 8. $x+y = 8, x1,x2>=0$ $C(n+r-1,r) = C(2+8-1,8)=C(9,8) =9$ Required probability = $\frac{9}{100} = 0.09$ Hence, (B) is the correct option! chauhansunil20th answered Jan 3, 2019 • selected Jan 17, 2019 by Shaik Masthan chauhansunil20th comment Share Follow See all 3 Comments See all 3 3 Comments reply bhanu kumar 1 commented Jan 3, 2019 reply Follow Share Ans is 0.09 Right , But how you uses combination for this please explain? 0 votes 0 votes chauhansunil20th commented Jan 3, 2019 reply Follow Share @bhanu kumar 1 number of non negative integral solutions. 0 votes 0 votes Krithiga2101 commented Jan 4, 2019 i edited by Krithiga2101 Jan 4, 2019 reply Follow Share Yes.Combinations are useful for larger values too. 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes chance that the sum of the digits on the page is equal to 8 are:- 8 ,17,26,35,44,53,62,71,80 so, ans= 9/100 = 0.09 MANSI_SOMANI answered Sep 13, 2022 MANSI_SOMANI comment Share Follow See all 0 reply Please log in or register to add a comment.