IQs of Employees

A large company employs workers whose IQs are distributed normally with mean 105 and standard deviation 12.5. Management uses this information to assign employees to projects that will be challenging, but not too challenging. What percentage of the employees would have IQs that satisfy the following criteria?

(a) less than 90

(b) more than 125

(c) between 100 and 120

(d) between 80 and 100