AP's have a common difference, not ratio.
There are 4 terms between #3 and #7
The difference is 30-6 = 24. Divide that among the 4 terms, and you see that d=6
So, if the first term is a, then
a + 2d = 3
a + 2*6 = 3
a + 12 = 3
a = -9
The 3 and 7 terms of an arithmetic progression are 6 and 30 respectively determine the common ratio and the first term
3 answers
DMGMT
malchus