Directions (next six questions): What should come in place of question mark (?) in the following number series ?
19 19.6 20.8 23.2 28
19(+0.6) 19.6(+1.2) 20.8(+2.4) 23.2(+4.8) 28(+9.6) 37.6
↓ ↓ ↓ ↓
0.6×2 1.2×2 2.4×2 4.8×2
18 19 24 37 66 ?
24 26 20 32 12
6 4 5 11 ? 189
19 10 11 18 38
606 201 66 21 6