Q1 of 102 Page 410

Find the sum of 23 terms of the AP 17, 12, 7, 2, –3, ….

To Find: The sum of 25 terms of the given AP series.


Sum of n terms of an AP with first term a and common difference d is given by



Here, a = 17, n = 23 and d = - 5





= - 874


Sum of 23 terms of the AP IS - 874.


More from this chapter

All 102 →
30

A side of an equilateral triangle is 24 cm long. A second equilateral triangle is inscribed in it by joining the midpoints of the sides of the first triangle; the process is continued. Find the perimeter of the sixth inscribed equilateral triangle.

aaa


 31

A man starts repaying a loan as the first instalment of 10000. If he increases the instalment by 500 every month, what amount will he pay in 30th instalment?

 2

Find the sum of 16 terms of the AP 6, 5 , 4 , 4, ….

 3

Find the sum of 25 terms of the AP , 2, 3, 4, ….