The ball drops 12m before the first bounce.
The subsequent bounces take the ball to 6m, then, 3m, etc. So the total distance is:
12+2(6+3+...) which can be written:
12+2×6(1+½+¼+...).
We have a geometric series with 6 terms:
12+12(1-(1/26))/(1-½)=12+24(63/64)=12+⅜×63=
12+189/8=12+23⅝=35⅝=35.625m.