Summation by Sigma Method
Trending Questions
Q.
If is added to giving due regard to significant figures, then the result will be
None of these
Q. The sum of first 9 terms of the series 131+13+231+3+13+23+331+3+5+…… is
- 71
- 192
- 96
- 142
Q. The 10th term common between the series 3+7+11+15+... and 1+6+11+16+... is
Q. If n∑k=1k(k+1)(k−1)=pn4+qn3+tn2+sn, where p, q, t, s are constant, then the correct option(s) is/are
- p=14
- q=12
- t=14
- s=−12
Q. If (x+1), 3x and (4x+2) are the first three terms of an A.P., then the value of 5th term is
Q. If 2+5+8+11+⋯upto n terms=610, then the value of n is
- 19
- 22
- 21
- 20
Q. The sum 3×1312+5×(13+23)12+22+7×(13+23+33)12+22+32+⋯ upto 10th term, is :
- 600
- 620
- 660
- 680
Q. The sum 10∑r=1(r2+1)×(r!) is equal to:
- 10×(11!)
- 11×(11!)
- (11!)
- 101×(10!)
Q. A series, whose nth term is (nx)+y, then sum of r terms will be :
- {r(r+1)2x}+ry
- {r(r−1)2x}
- {r(r−1)2x}2−xy
- {r(r+1)2x}−rx
Q. The sum of first 12 terms of the series 131+13+231+3+13+23+331+3+5+........ is
- 204.5
- 126.25
- 216.5
- 156.25
Q. If n∑r=1tr=n∑k=1k∑j=1j∑i=1(2), then t5 is
- 20
- 30
- 42
- 24
Q. If n∑k=1k∑m=1m2=an4+bn3+cn2+dn+e, then
- a+c=b+d
- d>a+c
- a+b=c
- b=2d+e
Q. The value of 3×1312+5×(13+23)12+22+7×(13+23+33)12+22+32+⋯ upto 10 terms, is
- 600
- 620
- 660
- 680