The answer is C because the formula is 2 x pai x radius
34.1754 is the answer because if 50 km an hour is 31.0685 just add the other km's
3×2+14=20
20×3+18=78
78×4+22=334
334×5+26=1696
1696×6+30=10206
Hence, the question mark should be replaced by 10206