Question 132372
it rebounds always the half

76,38,19 so the answer is 9.5

-3,-9,-14, -42,-47,-141

first you do -3*3=-9 after that you substract 5
-9-5=-14
after that you do -14*3=-42 

the pattern is :
multply by 3, substract 5.......

-3*3=-9
-9-5=-14
-14*3=-42
-42-5=-47
-47*3=-141
-141-5=-146
-146*3=-438

......