Notifications
Clear all
Arithmetic Progressions
1
Posts
2
Users
0
Likes
212
Views
0
31/05/2021 11:29 am
Topic starter
An A.P. consists of 50 terms of which 3rd term is 12 and the last term is 106. Find the 29th term.
1 Answer
0
31/05/2021 11:31 am
Given that,
3rd term, a3 = 12
50th term, a50 = 106
We know that,
an = a+(n−1)d
a3 = a+(3−1)d
12 = a+2d ……………. (i)
In the same way,
a50 = a + (50−1)d
106 = a + 49d ……………. (ii)
On subtracting equation (i) from (ii), we get
94 = 47d
d = 2 = common difference
From equation (i), we can write now,
12 = a+2(2)
a = 12−4 = 8
a29 = a+(29−1) d
a29 = 8+(28)2
a29 = 8+56 = 64
Therefore, 29th term is 64.