we know that
1 ft-------> is equal to 12 in
step 1
find the area of the walk
18 in wide--------> convert to ft
18/12=1.5 ft
area=1.5*32------> 48 ft²
step 2
find the cost at $2.10 a square foot
multiply 48 ft² by $2.10
48*2.1=$100.80
therefore
the answer is
$100.80
