Arts (English Medium) कक्षा ११ - CBSE Question Bank Solutions

If, S₁ is the sum of an arithmetic progression of 'n' odd number of terms and S₂ the sum of the terms of the series in odd places, then \[\frac{S_1}{S_2}\] = 

If in an A.P., S_n = n²p and S_m = m²p, where S_r denotes the sum of r terms of the A.P., then S_p is equal to

If the 6th, 7th and 8th terms in the expansion of (x + a)ⁿ are respectively 112, 7 and 1/4, find x, a, n.

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If in an A.P., the pth term is q and (p + q)th term is zero, then the qth term is

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The 10th common term between the A.P.s 3, 7, 11, 15, ... and 1, 6, 11, 16, ... is

If the 2nd, 3rd and 4th terms in the expansion of (x + a)ⁿ are 240, 720 and 1080 respectively, find x, a, n.

Find a, b and n in the expansion of (a + b)ⁿ, if the first three terms in the expansion are 729, 7290 and 30375 respectively.

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\[\text { If in an A . P } . S_n = n^2 q \text { and } S_m = m^2 q, \text { where } S_r \text{ denotes the sum of r terms of the A . P  . , then }S_q \text { equals }\]

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Let S_n denote the sum of first n terms of an A.P. If S_2n = 3S_n, then S_3n : S_n is equal to

If the term free from x in the expansion of  \[\left( \sqrt{x} - \frac{k}{x^2} \right)^{10}\]  is 405, find the value of k.

If p is a real number and if the middle term in the expansion of  \[\left( \frac{p}{2} + 2 \right)^8\] is 1120, find p.

Write the middle term in the expansion of `((2x^2)/3 + 3/(2x)^2)^10`.

Write the middle term in the expansion of  \[\left( x + \frac{1}{x} \right)^{10}\]

Write the coefficient of the middle term in the expansion of \[\left( 1 + x \right)^{2n}\] . 

Find the sum of the coefficients of two middle terms in the binomial expansion of  \[\left( 1 + x \right)^{2n - 1}\]

Write the total number of terms in the expansion of  \[\left( x + a \right)^{100} + \left( x - a \right)^{100}\] .

If in the expansion of (a + b)ⁿ and (a + b)ⁿ + 3, the ratio of the coefficients of second and third terms, and third and fourth terms respectively are equal, then n is

Find the centroid of a triangle, mid-points of whose sides are (1, 2, –3), (3, 0, 1) and (–1, 1, –4). 

If A and B are the sums of odd and even terms respectively in the expansion of (x + a)ⁿ, then (x + a)²ⁿ − (x − a)²ⁿ is equal to

The centroid of a triangle ABC is at the point (1, 1, 1). If the coordinates of A and B are (3, –5, 7) and (–1, 7, –6) respectively, find the coordinates of the point C.