a batch of 15 granite slabs is mined, and 4 have defects. If the manager spot checks 3 slabs at random, what is the probability that at least 1 slab is defective?? how do i do this?
P(a least 1 is defective)
=1-P(none are defective)
$$\\=1-\left(\frac{11}{15}\times \frac{10}{14} \times \frac{9}{13}\right)$$
