Consider an ERD for a beauty salon in which there is a superclass entity EMPLOYEE with four subclasses:
CASHIER, HAIR_STYLIST, NAIL_TECH, and MANAGER.
A HAIR_STYLIST is a specialization of EMPLOYEE and can also inherit from the MANAGER class. Which of the following terms best describes the relationship between HAIR_STYLIST, EMPLOYEE, and MANAGER?
O multiple inheritance
O tree structure
O single inheritance
O partial and disjoint

Partial and disjoint

Explanation:

Since there is overlapping in relationship of HAIR_STYLIST and MANAGER it can't be tree structure.

A MANAGER can or can't be HAIR_STYLIST. In order for the relationship to be multiple inhertiance am entity in sub-class has to be union of all subclasses

In single inheritance, a sub-class has to be a union of a single super class.

In partial and disjoint, some entity in super class may or may not be related to a sub-class.

the formula for work is

f*d

therefore work=2.0n*3.0=6n*m