In an A.P., the sum of first n terms is \[\frac{3{{n}^{2}}}{2}+\frac{1 – McqOptions

MCQOPTIONS

1.	In an A.P., the sum of first n terms is \[\frac{3{{n}^{2}}}{2}+\frac{13n}{2}.\]Find its 25th term.
A.	80
B.	120
C.	60
D.	78
Answer» B. 120

Discussion

No Comment Found

Related MCQs

In an A.P., the sum of first n terms is \[\frac{3{{n}^{2}}}{2}+\frac{13n}{2}.\]Find its 25th term.
If \[\frac{{{a}^{n+1}}+{{b}^{n+1}}}{{{a}^{n}}+{{b}^{n}}}\]is the A.M. between a and b, then find the value of n.
What is the sum to 'n' terms of the series\[\sqrt{5},\sqrt{20},\sqrt{45},\sqrt{80},.....?\]
In an arithmetic progression, if\[{{\text{t}}_{\text{p}}}\text{=q},{{\text{t}}_{\text{q}}}=\text{p},\]find \[{{\text{t}}_{\text{pq}}}\].
If\[{{\text{1}}^{\text{3}}}+{{\text{2}}^{\text{3}}}+.....+{{\text{m}}^{\text{3}}}=\text{3}0\text{25}\], find m.
A roll of thread 907i cm long is cut into 5 parts to make up 5 circles as shown in the figure. The radii of the circles increase by 1 cm consecutively. Find the radius of the smallest circle.
A secondary school had an enrolment of 1620 students in the year 2009 which increases by 150 students per year. What was the enrolment in the year 2013?
Find the sum of the arithmetic progression, \[x-2y,2x-y,3x......11x+8y\].
A manufacturer of laptop produced 6000 units in 3rd year and 7000 units in the 7th year. Assuming that production increases uniformly by a fixed number every year, find the production in the 5th year.
A circle with area \[{{A}_{1}}\] is contained in the interior of a larger circle with area \[{{A}_{1}}+{{A}_{2}}.\] If the radius of the larger circle is 3 units and \[{{A}_{1}},{{A}_{2}},{{A}_{1}}+{{A}_{2}}\]are in A.P., then the radius of the smaller circle is ___.