Question

If the second term of an ap is 8and the 5 term is 17 find its 19 term

Answer 1

Given: a2=8,a5=17
To find:a19
Solution:
a2=a+d=8,
a5=a+4d=17

Now, by elimination method
+a+4d=+17
+a+ d=+8
- - -
3d=9
d=3,
a+4(3)=17
a=5

So,a19=a+18d
=5+18(3)
=59

Therefore, Nineteenth term,a19=59