Sequence And Series · Mathematics · NDA

What is the remainder when $2^{120}$ is divided by 7?

If $a, b, c$ are in AP; $b, c, d$ are in GP; $c, d, e$ are in HP, then which of the following is/are correct?1. $a, c,$ and $e$ are in GP2. $\frac{1}{...

If $a, b, c$ are in HP, then what is $\frac{1}{b-a} + \frac{1}{b-c}$ equal to? 1. $\frac{2}{b}$2. $\frac{1}{a} + \frac{1}{c}$3. $\frac{1}{2} \left( \f...

If the nth term of a sequence is $\frac{2 n+5}{7}$, then what is the sum of its first 140 terms? ...

If (a + b), 2b, (b + c) are in HP, then which one of the following is correct?

Let t1, t2, t3 ... be in GP. What is $\rm \left(t_1 t_3 \ldots t_{21}\right)^{\frac{1}{11}}$ equal to ?...

What is a1 + a5 - a10 - a15 - a20 - a25 + a30 + a34 equal to ?...

What is $\displaystyle \sum_{n=1}^{34} a_n$ equal to ?

If logxa, ax and logbx are in GP, then what is x equal to ? 

If $2^{\frac{1}{c}}, 2^{\frac{b}{a c}}, 2^{\frac{1}{a}}$ are in GP, then which one of the following is correct ? 

The first and the second terms of an AP are $\frac{5}{2}$ and $\frac{23}{12}$ respectively. If nth term is the largest negative term, what is the...

In an AP, the first term is x and the sum of the first n terms is zero. What is the sum of next m terms ?

p, q, r and s are in AP such that p + s = 8 and qr = 15. What is the difference between largest and smallest numbers ?  

If G is the geometric mean of numbers 1, 2, 22, 23,.....2n-1, then what is the value of 1 + 2log2G ?

If H is the harmonic mean of numbers 1, 2, 22, 23, ......2n-1 what is n/H equal to ?