Engineering Board Exam Reviewer · Sequences and Series · hard
The pages of a book are numbered 1 through n. When the page numbers of the book were added, one of the page numbers was mistakenly added twice, resulting in an incorrect sum of 1986. What was the page number that was added twice?
- 33
- 35
- 36
- 34
Answer
A. 33
Solution
Let n=true number of pages. Testing n=62 gives the correct sum n(n+1)/2 = 1953. The repeated page number is the difference: 1986-1953=33.
More Sequences and Series questions
- What is the first four terms of the sequence whose general term is n2+1?
- Find the sum of the first 5 terms in the sequence whose general term is 2n-1.
- Determine the 5th term of the sequence whose sum of n terms is given by (2n+3-5).
- Find the 30th term of the arithmetic progression 4, 7, 10,
- Four positive integers form an arithmetic progression. If the product of the 1st and the last term is 70 and the product of the 2nd and…
- How many terms of the progression 3, 5, 7, should there be so that their sum will be 2600?
- What is the sum of all odd integers between 10 and 500?
- What is the sum of all even integers from 10 to 500?
- The sum of an infinite geometric series is 18, and the sum of the squares of its terms is 108. Find the first term.
- Find the sum of the first 12 terms of the geometric sequence 3, 6, 12,