Chapter 10 - Arithmetic Progression Exercise Ex. 10(C)

Question 1

Find the sum of the first 22 terms of the A.P.: 8, 3, -2, ………..

Solution 1

Question 2

How many terms of the A.P. :

24, 21, 18, ……… must be taken so that their sum is 78?

Solution 2

Question 3

Find the sum of 28 terms of an A.P. whose n^th term is 8n - 5.

Solution 3

Question 4(i)

Find the sum of all odd natural numbers less than 50

Solution 4(i)

Question 4(ii)

Find the sum of first 12 natural numbers each of which is a multiple of 7.

Solution 4(ii)

Question 5

Find the sum of first 51 terms of an A.P. whose 2^nd and 3^rd terms are 14 and 18 respectively.

Solution 5

Question 6

The sum of first 7 terms of an A.P is 49 and that of first 17 terms of it is 289. Find the sum of first n terms

Solution 6

Question 7

The first term of an A.P is 5, the last term is 45 and the sum of its terms is 1000. Find the number of terms and the common difference of the A.P.

Solution 7

Question 8

Find the sum of all natural numbers between 250 and 1000 which are divisible by 9.

Solution 8

Question 9

The first and the last terms of an A.P. are 34 and 700 respectively. If the common difference is 18, how many terms are there and what is their sum?

Solution 9

Question 10

In an A.P, the first term is 25, n^th term is -17 and the sum of n terms is 132. Find n and the common difference.

Solution 10

Question 11

If the 8^th term of an A.P is 37 and the 15^th term is 15 more than the 12^th term, find the A.P. Also, find the sum of first 20 terms of A.P.

Solution 11

Question 12

Find the sum of all multiples of 7 lying between 300 and 700.

Solution 12

Question 13

The sum of n natural numbers is 5n² + 4n. Find its 8^th term

Solution 13

Question 14

The fourth term of an A.P. is 11 and the eighth term exceeds twice the fourth term by 5. Find the A.P and the sum of first 50 terms

Solution 14