Answer:
221754385964.9123
Step-by-step explanation:
Convert miles to nanometer
1 mile = 1.6 km
1 km = 1×10³×10³×10³×10³ nm
1 mile = 1.6×10¹² nm
So,
158 miles = 158×1.6×10¹² = 252.8×10¹² nm
Length of each molecule = 1140 nm
Number of molecules = Total length / Length of each molecule

There are 221754385964.9123 number of molecules in a stretch of 158 miles