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?

b1 produces $20$% of the products. Of these $3$% are defective.

Hence, defective machines $=\frac{3}{100}\times20=0.6$%, and non-defective $= (20-0.6)\%=19.4$%

b2 produces $15$% of the products. Of these, $7$% are defective.

Hence, defective machines $=\frac{7}{100}\times15=1.05\%$, and non-defective $=(15-1.05)\%=13.95$%

b3 produces $32$% of the products. Of these $2$% are defective.

Hence, defective machines $=\frac{2}{100}\times32=0.64\%$, and non-defective $=(32-0.64)\%=31.36$%

Hence, percentage of non-defective products $=19.4+13.95+31.36=64.71$%, which is approximately $64\%$