It is difficult to cut cloth using a pair of scissors with blunt blades because:

i. Blunt blades (sharp) have large surface area than that of sharp-edged blades.

ii. As we know that pressure is inversely proportional to the area. Larger the area, smaller will be the pressure.

iii. Hence, in blunt blades, applied force produces very less pressure.

iv. Due to low pressure, this becomes difficult to cut the cloth from blunt blades.