Take a Quiz
All Products
Brain Games
ProProfs.com
Change Image Delete
Answered Nov 06, 2017
ANSWER= 513.
3,9,33,129,?
9=3*3+(3-3)
33=9*3+(9-3)
129=33*3+(33-3)
Thus, ?=129*3+(129-3)=487+126=513...
Answered Nov 06, 2016
Forgot your password?