Much of what we know about left and right hemisphere specializations comes from the study of people who had split-brain surgery. this surgery select one:

a. splits the lobes of the brain apart.
b. severs the corpus callosum between hemispheres.
c. severs the nerves from the spinal cord to the right hemisphere.
d. severs the substantia nigra between hemispheres.

Assume that there is a 11% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on four independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?