The population of Ectenia is 100 people:40 work full-time, 20 work half time but would prefer to work full-time, 10 are looking for a job, 10 would like to work out are so discouraged they have given up looking, 10 are not interested in working because they are full-time students, and 10 and retired. What is the number of unemployed?
a.10
b. 20 c. 30
d. 40