Pens are packed in boxes.
There are 6 pens in each box.
The probability that any pen is defective is 0.1.
A box of pens is picked at random.
Find the probability that the box contains exactly one defective pen.
Give your answer correct to 3 significant figures.
You may use (p+q)6=p6+6p5q+15p4q2+20p3q3+15p2q4+6pq5+q6(p + q)^6 = p^6 + 6p^5q + 15p^4q^2 + 20p^3q^3 + 15p^2q^4 + 6pq^5 + q^6(p+q)6=p6+6p5q+15p4q2+20p3q3+15p2q4+6pq5+q6.
Find the probability that the box contains at most one defective pen.
Give your answer correct to 3 significant figures.
Suki buys 125 boxes of pens.
Find an estimate for the number of boxes that contain less than two defective pens.
