The sum of first 20 terms of the sequence 0.7, 0.77, 0.777..... is
If the sum of first 75 terms of an AP 2625, then the 38th term of an AP is
The sum of first four terms of a geometric progression (G.P.) is 65/12 and the sum of their respective reciprocals is 65/18 If the product of first three terms of the G.P. is 1 and the third term is m, then 2m is
Let S1 be the sum of first 2n terms of an arithmetic progression. Let S₂ be the sum of first 4n terms of the same arithmetic progression. If (S₂-S1) is 1000, then the sum of the first 6n terms of the arithmetic progression is equal to
Let α and ẞ be the roots of equation px² + qx + r = 0, p not equal to zero. If p, q and r are in AP and 1/α + 1/ẞ = 4, then the value |α-ẞ|
If the sum of an infinite GP a, ar, ar², ar³,... is 15 and the sum of the squares of its each term is 150, then the sum of ar², ar⁴, ar⁶,... is
Let Sn, denote the sum of first n terms of an arithmetic progression. If S10 = 530, S5 = 140, then S20 – S6 is equal to
In a triangle, the lengths of two larger sides are 10 cm and 9 cm. If the angles of the triangle are in AP, then the length of the third side is
The sum of first three terms of a GP is 7/9 and their product is -8/27. Find the common ratio of the series
Let Sn, be the sum of the first n terms of an arithmetic progression, If S3n= 3S2n, then the value of S4n/S2n is
