Based on the survey conducted by a municipal administration in the Netherlands, Monday appeared to be managements' preferred day for laying off workers. Of the total number of workers laid off in a given period, 30% were on Monday, 25% on Tuesday, 20% on Wednesday, 13% on Thursday, and 12% on Friday. If a random sample of 15 layoffs is taken, what is the probability that
a. Five were laid off on Monday.
b. Four were laid off on Tuesday.
c. Three were laid off on Wednesday.
d. Two were laid off on Thursday.
e. One was laid off on Friday.