Check whether – 150 is a term of the AP : 11, 8, 5, 2 . .
The given list of number is
11, 8, 5, 2,.....
a2 – ax = 8 – 11 = –3
a2 – a2 = 5 – 8 = –3
And, a4 – a3 = 2 – 5 = –3
i.e., ak + 1 – ak is the same every time. So, the given list of numbers form an A .P. with first term a = 11 and the common difference d = –3.
Let –150 be the nth term of the given A .P.
Then, an = -150
a + (n - 1)d = - 150
11 + (n - 1) (-3) = - 150
-3(n - 1 ) = - 150 -11
-3 (n - 1) = -161
3 ( n - 1) = - 161
3(n - 1) = 161
But n should be a positive integer. So, 150 is not a term of
11, 8, 5, 2,.......
An AP consists of 50 terms of which 3rd term is 12 and the last term is 106. Find the 29th term.
Two APs have the same common difference. The difference between their 100th terms is 100, what is the difference between their 1000th terms?