A Styrofoam Cooler Has a Surface Area of 2,700 Cm²

A Styrofoam cooler has a surface area of 2,700 cm² and a wall thickness of 3.00 cm. Styrofoam has a thermal conductivity of 0.010 W/m °C. A 2.00 kg block of ice is placed inside the cooler that has a temperature inside of 2°C. When the temperature outside is 30.0°C, the ice lasts for 8.00 hours. If the temperature outside becomes 20.0°C, then how long will the ice last? Ignore the effect of the air inside the cooler.

A) 20.3 hr
B) 18.5 hr
C) 12.4 hr
D) 10.1 hr
E) 8.5 hr