Question2. (6th January 2014) : One leaf from a book torn off having page nos. 1 to 51. Sum of
remaining page numbers is 1313. Which page number was torn off from the book ?
Answers and explanations are welcome in the comments. The correct answer will be given tomorrow.
Correct Answer is : Page no. 13.
ReplyDeleteExplanation : Sum of page nos. From 1 to 51 with arithmetic progession (AP) series n (n+1)/2.
Put 51 as the value of 'n' you will get a sum 1326
Now subtract 1313 from correct sum. So you will know page no 13 is torn off (if one page no. Mentioned on each page)