In a factory there are three types of machines b1, b2, and b3 which produces 20%, 15%, and 32% of the total products respectively. Further, machines b1, b2, and b3 which produces 3%, 7%, and 2% defective products respectively. Find the percentage of non-defective products?

Let the total no of products be 'P' . Now, as b1, b2, b3 are producing 20%, 15% and 32% :
b1  is producing = (0.2)P
b2 is producing = (0.15)P
b3 is producing = (0.32)P

As b1,b2,b3 produces 3%, 7% and 2% defective products respectively, it implies they make 97%, 93%, 98% products non-defective .
Hence, b1's no. of non defective products = 0.97(0.2)P = 0.194 P
b2's no of non defective products = 0.93 (0.15) P = 0.1395 P
b3's no of non defective products = 0.98 (0.32) P = 0.3136 P

Total non defective products = P (0.194 + 0.1395 + 0.3136) = 0.6471 P
Therefore, percentage of non defective products =  64.71 %