an Arithmetic progression is given by k,2k/3,k/3,o.find the sixth term,the nth term and if the 20th term is 15 find k

2 answers

show the steps to follow to get the answers
the common difference is -k/3
so, Tn = k-(n-1)(k/3) = k - n/3 k + k/3 = (4-n)k/3
Now find k since T20 = 15