Question

An A.P consists of 50 terms out of which 3rd term is 12 & last term is 106. Find the 29th term

Answer 1

nth term = a + (n-1)d,

3rd term = a + 2d,

according to data, it is equal to 12,

So a+ 2d = 12 ........(1),

Last term = a+49d ,

according to the data it is equal to 106,

=>a + 49d = 106 ........(2),

Subtract (2) and (1) :

a + 49d - a - 2d = 106-12,
47d = 94
=> d = 2,

Substitute it in 1,

=> a = 12-4 = 8,

Now 29th term equals,

a + 28d,
=> 8 + 56 = 64,

Therefore the 29th term is 64 !!!!!