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महाराष्ट्र राज्य शिक्षण मंडळएस.एस.सी (इंग्रजी माध्यम) इयत्ता १० वी

What is the Sum of First 10 Terms of the A. P. 15,10,5,........?

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प्रश्न

What is the sum of first 10 terms of the A. P. 15,10,5,........?

पर्याय

  • (A) -75

  • (B) -125

  • (C) 75

  • (D) 125

MCQ
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उत्तर

(A) -75

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2018-2019 (March) Balbharati Model Question Paper Set 2

संबंधित प्रश्‍न

Find the sum of all natural numbers between 250 and 1000 which are exactly divisible by 3


How many terms of the series 54, 51, 48, …. be taken so that their sum is 513 ? Explain the double answer


Check whether -150 is a term of the A.P. 11, 8, 5, 2, ....


An A.P. consists of 50 terms of which 3rd term is 12 and the last term is 106. Find the 29th term of the A.P.


Show that a1, a2,..., an... form an AP where an is defined as below:

an = 9 − 5n

Also, find the sum of the first 15 terms.


The first term of an AP is p and its common difference is q. Find its 10th term.


If the sum of first p terms of an AP is (ap2 + bp), find its common difference.


Find the first term and common difference for the A.P.

`1/4,3/4,5/4,7/4,...`


In an A.P. sum of three consecutive terms is 27 and their product is 504, find the terms.
(Assume that three consecutive terms in A.P. are a – d, a, a + d).


The Sum of first five multiples of 3 is ______.


If first term of an A.P. is a, second term is b and last term is c, then show that sum of all terms is  \[\frac{\left( a + c \right) \left( b + c - 2a \right)}{2\left( b - a \right)}\].


If the sum of first p terms of an A.P. is equal to the sum of first q terms then show that the sum of its first (p + q) terms is zero. (p ≠ q)


There are 25 rows of seats in an auditorium. The first row is of 20 seats, the second of 22 seats, the third of 24 seats, and so on. How many chairs are there in the 21st row ?


In an A.P., the sum of first ten terms is −150 and the sum of its next ten terms is −550. Find the A.P.


If the nth term of an A.P. is 2n + 1, then the sum of first n terms of the A.P. is 


Find the sum of all members from 50 to 250 which divisible by 6 and find t13.


In an A.P. (with usual notations) : given d = 5, S9 = 75, find a and a


Determine the sum of first 100 terms of given A.P. 12, 14, 16, 18, 20,......

Activity :- Here, a = 12, d = `square`, n = 100, S100 = ?

Sn = `"n"/2 [square + ("n" - 1)"d"]`

S100 = `square/2 [24 + (100 - 1)"d"]`

= `50(24  +  square)`

= `square`

= `square`


Find the sum of natural numbers between 1 to 140, which are divisible by 4.

Activity: Natural numbers between 1 to 140 divisible by 4 are, 4, 8, 12, 16,......, 136

Here d = 4, therefore this sequence is an A.P.

a = 4, d = 4, tn = 136, Sn = ?

tn = a + (n – 1)d

`square` = 4 + (n – 1) × 4

`square` = (n – 1) × 4

n = `square`

Now,

Sn = `"n"/2["a" + "t"_"n"]`

Sn = 17 × `square`

Sn = `square`

Therefore, the sum of natural numbers between 1 to 140, which are divisible by 4 is `square`.


If the sum of first n terms of an AP is An + Bn² where A and B are constants. The common difference of AP will be ______.


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