Quick Note: I'm pretty sure you meant 180LBS and not 1801bs, so I'm using 180, but if it was 1801 please tell me
Percent of change = [tex] \frac{V2 - V1}{V1} *100[/tex]
Substitute 180 for V2 and 160 for V1
Percent of change = [tex] \frac{180-160}{160} * 100[/tex]
Solve
Percent of change = [tex] \frac{20}{160} *100[/tex]
Percent of change = 0.125 x 100
Percent of change = 12.5%