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
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 Sn, denote the sum of first n terms of an arithmetic progression. If S10 = 530, S5 = 140, then S20 – S6 is equal to
Let Sn, be the sum of the first n terms of an arithmetic progression, If S3n= 3S2n, then the value of S4n/S2n is
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
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
The sum of first 20 terms of the sequence 0.7, 0.77, 0.777..... is
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|
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
If the sum of first 75 terms of an AP 2625, then the 38th term of an AP is
