Advertisements
Advertisements
Question
What is the sum of first 10 terms of the A. P. 15,10,5,........?
Options
(A) -75
(B) -125
(C) 75
(D) 125
Advertisements
Solution
(A) -75
APPEARS IN
RELATED QUESTIONS
Find the sum of two middle most terms of the AP `-4/3, -1 (-2)/3, ..., 4 1/3.`
If the numbers (2n – 1), (3n + 2) and (6n – 1) are in AP, find the value of n and the numbers.
The sum of the first n terms of an AP is given by Sn = (3n2 – 4n). Find its
- nth term,
- first term and
- common difference.
Find the sum of all natural numbers between 200 and 400 which are divisible by 7.
Write an A.P. whose first term is a and common difference is d in the following.
a = –3, d = 0
Write an A.P. whose first term is a and common difference is d in the following.
a = –1.25, d = 3
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 \[\frac{\left( a + c \right) \left( b + c - 2a \right)}{2\left( b - a \right)}\].
Find the sum of n terms of the series \[\left( 4 - \frac{1}{n} \right) + \left( 4 - \frac{2}{n} \right) + \left( 4 - \frac{3}{n} \right) + . . . . . . . . . .\]
Write the value of a30 − a10 for the A.P. 4, 9, 14, 19, ....
Write 5th term from the end of the A.P. 3, 5, 7, 9, ..., 201.
Two cars start together in the same direction from the same place. The first car goes at uniform speed of 10 km h–1. The second car goes at a speed of 8 km h–1 in the first hour and thereafter increasing the speed by 0.5 km h–1 each succeeding hour. After how many hours will the two cars meet?
Mrs. Gupta repays her total loan of Rs. 1,18,000 by paying installments every month. If the installments for the first month is Rs. 1,000 and it increases by Rs. 100 every month, What amount will she pays as the 30th installments of loan? What amount of loan she still has to pay after the 30th installment?
The sum of first 14 terms of an A.P. is 1050 and its 14th term is 140. Find the 20th term.
First four terms of the sequence an = 2n + 3 are ______.
If the numbers n - 2, 4n - 1 and 5n + 2 are in AP, then the value of n is ______.
Find the sum of the integers between 100 and 200 that are
- divisible by 9
- not divisible by 9
[Hint (ii) : These numbers will be : Total numbers – Total numbers divisible by 9]
Show that the sum of an AP whose first term is a, the second term b and the last term c, is equal to `((a + c)(b + c - 2a))/(2(b - a))`
Find the sum of first 'n' even natural numbers.
Calculate the sum of 35 terms in an AP, whose fourth term is 16 and ninth term is 31.
Rohan repays his total loan of ₹ 1,18,000 by paying every month starting with the first installment of ₹ 1,000. If he increases the installment by ₹ 100 every month, what amount will be paid by him in the 30th installment? What amount of loan has he paid after 30th installment?
