So each 1 revolution it travels the distance around the rim of the wheele aka circumference
circumference=pi times diameter
diameter=21
circunference=pi times 21 or 21pi
so distance=number of revolutions times circunference
number of revolutions=3
subsitute
distance=3 times 21pi
distance=63pi
answer is 63pi
or aprox pi to 3.14 and do 63 times 3.14=197.82
aprox 197.82 inches
30 divided by 2.5
so 12 hours until he catches 30 bad guys
1/5= .2 + 1= 1.2 is 1 1/5 as a decimal
I assume the denominator is (4-√3)
Multiple both top and bottom by (4+√3)
[5(4+√3)]/[(4-√3)(4+√3)]
=[20+5√3]/[4²-(√3)²]
=[20+5√3]/13