2. assume a 15 cm diameter wafer has a cost of 12, contains 84 dies, and has 0.020 defects/cm2. assume a 20 cm diameter wafer has a cost of 15, contains 100 dies, and has 0.031 defects/cm2. (a) find the yield for both wafers. as part of this problem, you will want to derive a formula for die area (note that this will be an approximation).cost per die= cost per wafer / dies per wafer x yielddies per wafer =wafer area/ die areayield= 1 / (1+ (defects per area x die area/2))^2for both wafers, give your calculated value (use 3.14 for π) of die area (in cm2, two decimal places) and the value of yield to four decimal places.(b) find the cost per die for both wafers. the problem does not specify the unit of cost (it is simply 12 and 15). therefore, your answer will not have a specific unit either.