Q15 of 105 Page 139

Find the 20thterm from the end of the AP : 3, 8, 13, …., 253.

Given:

First term (a) = 3


Common difference (d) = n2 – n1 = 8-3 = 5


an = a + (n-1)d


a20 = a + (20-1)d


= 3 +19×5


= 98


More from this chapter

All 105 →
13

For what value of n, are the nth terms of two APs: 63, 65, 67, …. And 3, 10, 17, …. Equal?

 14

Determine the AP whose third term is 16 and the 7thterm exceeds the 5thterm by 12.

 16

The sum of the 4th and 8thterms of an AP is 24 and the sum of the 6th and 10th terms is 44. Find the first three terms of the AP.

 17

Subba Rao started work in 1995 at an annual salary of Rs. 5000 and received an increment of Rs. 200 each year. In which year did his salary reach Rs. 7000?