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Find an A.P. in which the sum of any number of terms is always three times the squared number of these terms.
Concept: undefined >> undefined
If the sum of n terms of an A.P. is nP + \[\frac{1}{2}\] n (n − 1) Q, where P and Q are constants, find the common difference.
Concept: undefined >> undefined
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The sums of n terms of two arithmetic progressions are in the ratio 5n + 4 : 9n + 6. Find the ratio of their 18th terms.
Concept: undefined >> undefined
The sums of first n terms of two A.P.'s are in the ratio (7n + 2) : (n + 4). Find the ratio of their 5th terms.
Concept: undefined >> undefined
If \[\frac{1}{a}, \frac{1}{b}, \frac{1}{c}\] are in A.P., prove that:
\[\frac{b + c}{a}, \frac{c + a}{b}, \frac{a + b}{c}\] are in A.P.
Concept: undefined >> undefined
If \[\frac{1}{a}, \frac{1}{b}, \frac{1}{c}\] are in A.P., prove that:
a (b +c), b (c + a), c (a +b) are in A.P.
Concept: undefined >> undefined
If a2, b2, c2 are in A.P., prove that \[\frac{a}{b + c}, \frac{b}{c + a}, \frac{c}{a + b}\] are in A.P.
Concept: undefined >> undefined
If a, b, c is in A.P., then show that:
a2 (b + c), b2 (c + a), c2 (a + b) are also in A.P.
Concept: undefined >> undefined
If a, b, c is in A.P., then show that:
b + c − a, c + a − b, a + b − c are in A.P.
Concept: undefined >> undefined
If a, b, c is in A.P., then show that:
bc − a2, ca − b2, ab − c2 are in A.P.
Concept: undefined >> undefined
If \[\frac{b + c}{a}, \frac{c + a}{b}, \frac{a + b}{c}\] are in A.P., prove that:
\[\frac{1}{a}, \frac{1}{b}, \frac{1}{c}\] are in A.P.
Concept: undefined >> undefined
If \[\frac{b + c}{a}, \frac{c + a}{b}, \frac{a + b}{c}\] are in A.P., prove that:
bc, ca, ab are in A.P.
Concept: undefined >> undefined
If a, b, c is in A.P., prove that:
(a − c)2 = 4 (a − b) (b − c)
Concept: undefined >> undefined
If a, b, c is in A.P., prove that:
a2 + c2 + 4ac = 2 (ab + bc + ca)
Concept: undefined >> undefined
If a, b, c is in A.P., prove that:
a3 + c3 + 6abc = 8b3.
Concept: undefined >> undefined
If \[a\left( \frac{1}{b} + \frac{1}{c} \right), b\left( \frac{1}{c} + \frac{1}{a} \right), c\left( \frac{1}{a} + \frac{1}{b} \right)\] are in A.P., prove that a, b, c are in A.P.
Concept: undefined >> undefined
Show that x2 + xy + y2, z2 + zx + x2 and y2 + yz + z2 are consecutive terms of an A.P., if x, y and z are in A.P.
Concept: undefined >> undefined
If x, y, z are in A.P. and A1 is the A.M. of x and y and A2 is the A.M. of y and z, then prove that the A.M. of A1 and A2 is y.
Concept: undefined >> undefined
Insert five numbers between 8 and 26 such that the resulting sequence is an A.P.
Concept: undefined >> undefined
A man saved Rs 16500 in ten years. In each year after the first he saved Rs 100 more than he did in the receding year. How much did he save in the first year?
Concept: undefined >> undefined
