A market research company uses a large number of typists to enter data in a computer database. The time taken for new typists to learn computer system is known to have Normal distribution with mean of 130 minutes and standard deviation of 20 minutes. A candidate is automatically appointed if he or she learns the computer system in less than 100 minutes. A cut-off time is set at the slowest 40% of learning distribution. Anyone slower than this cut-off time isn't hired.
What proportion of candidates will be automatically hired?
A. 0.023
B. 0.067
C. 0.159
D. 0.309