we know that
A bowling lane is 42 inches wide and 60 feet long
1 ft-------> 12 in
60 ft-----> X
X=60*12------> X=720 in
[the length of a circumference]=2*pi*r
for r=8.5/2------> r=4.25 in
[the length of a circumference]=2*pi*4.25---------->26.69 in
if 26.69 in represent---------------> 1 revolution
720 in (bowling lane)------------> X
X=720/26.69------> X=26.98 revolution
the answer is
26 revolutions