Three manufacturing plants, say A, B and C, produce 12, 30 and 58 percent of a company's output respectively. The manager of plant C is very quality conscious and only 1% of the items from that plant are defective. Plants A and B have defective rates of 3% and 5% respectively.

What is the probability that a randomly-chosen item from the company's warehouse is defective?

(Note: Write the formula and /or notation you are using before putting the numbers in. Show your work)