5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
Rule
This topic has expert replies
-
Neo Anderson
- Senior | Next Rank: 100 Posts
- Posts: 92
- Joined: Thu Oct 06, 2011 8:06 am
- Thanked: 18 times
as you said it is a linear sequence, consider it as ax+b
given for x=1 ax+b equals -2, i.e. a+b = -2 ---(i)
also that for x=2, 2a+ b= 18 ---(ii)
from (i) and (ii)
a = 20, b = -22
thus the rule is 20x-22,
test for 3rd term => 3 X 20 - 22 = 38
given for x=1 ax+b equals -2, i.e. a+b = -2 ---(i)
also that for x=2, 2a+ b= 18 ---(ii)
from (i) and (ii)
a = 20, b = -22
thus the rule is 20x-22,
test for 3rd term => 3 X 20 - 22 = 38
