If the sum of the first 11 terms of an arithmetic progression equals that of the first 19 terms, then what is the sum of the first 30 terms?
Consider the sequence of numbers a1, a2, a3, ... to infinity where a1 = 81.33 and a2 = –19 and
aj = aj–1 – aj–2 for What is the sum of the first 6002 terms of this sequence?
The integers 1, 2, …, 40 are written on a blackboard. The following operation is then repeated 39 times: In each repetition, any two numbers, say a and b, currently on the blackboard are erased and a new number a + b – 1 is written. What will be the number left on the board at the end?
The number of common terms in the two sequences 17, 21, 25, , 417 and 16, 21, 26, , 466 is
Let un+1 = 2un + 1 (n=0,1,2,....)and u0 = 0 Then u10 nearest to
If the harmonic mean between two positive numbers is to their geometric mean as 12 : 13; then the numbers could be in the ratio
Fourth term of an arithmetic progression is 8. What is the sum of the first 7 terms of the arithmetic progression?
Along a road lie an odd number of stones placed at intervals of 10m. These stones have to be assembled around the middle stone. A person can carry only one stone at a time. A man carried out the job starting with the stone in the middle, carrying stones in succession, thereby covering a distance of 4.8 km. Then the number of stones is
All the page numbers from a book are added, beginning at page 1. However, one page number was added twice by mistake. The sum obtained was 1000. Which page number was added twice?
For a Fibonacci sequence, from the third term onwards, each term in the sequence is the sum of the previous two terms in that sequence. If the difference in squares of 7th and 6th terms of this sequence is 517, what is the 10th term of this sequence?
The sum of 3rd and 15th elements of an arithmetic progression is equal to the sum of 6th, 11th and 13th elements of the same progression. Then which element of the series should necessarily be equal to zero?
The 288th term of the series a,b,b,c,c,c,d,d,d,d,e,e,e,e,e,f,f,f,f,f,f is
There are 8436 steel balls, each with a radius of 1 centimeter, stacked in a pile, with 1 ball on top, 3 balls in the second layer, 6 in the third layer, 10 in the fourth, and so on. The number of horizontal layers in the pile is
If the product of n positive real numbers is unity, then their sum is necessarily
If log3 2, log3 (2x 5), log3 (2x 7/2) are in arithmetic progression, then the value of x is equal to
In a certain examination paper, there are n questions. For j = 1,2 n, there are 2nj students who answered j or more questions wrongly. If the total number of wrong answers is 4095, then the value of n is