Question
Sun April 08, 2012 By:

the 4th and 12th term are in the ration 1:3 and T 15 = 60 . Find AP

Expert Reply
Mon April 09, 2012
We know that:
The general term of an A.P is given by:
an = a + (n-1)d, where a is the first term and d is the common difference.
 
Since, a4 : a12 = 1: 3
Solving this equation, we get 3a + 9d = a + 11 d which gives a = d
 
Also, it is given that T15 = 60
Thus, a + 14 d = 60
This gives, d = 4
Hence, a = d = 4
The required AP is
4, 8, 12, ...
Related Questions
Fri September 30, 2016

[(25)^2/3]^3/4 = ?

Ask the Expert