Solution :
Here, we need to perform JOIN operation of the students and registration.
Use NATURAL JOIN operator 
and so no need to specify Join condition.
Also we need to selection operator tp select only those course whose major in "philosophy".
Finally we projection operator π to project only distinct students name who took at least three courses.
![$\pi [\sigma_{\text{student's nam}e} [ \sigma(\text{three courses}) \Join \text{"Philosophy"}]]$](https://tex.z-dn.net/?f=%24%5Cpi%20%5B%5Csigma_%7B%5Ctext%7Bstudent%27s%20nam%7De%7D%20%5B%20%5Csigma%28%5Ctext%7Bthree%20courses%7D%29%20%5CJoin%20%5Ctext%7B%22Philosophy%22%7D%5D%5D%24)
Answer:
Rick has identified a cost risk.
Explanation:
Risk is the probability of loss in a given setting. Herein, the risk involved is the inadequate assessment of the costs involved to carry out the project usually as a result of poor pricing evaluation of resources required for the project. At the early stage of every project, effective and efficient cost estimation is needed because it provides a basis for estimation of the total costs, it helps distribute the cost budget, it eases decision making and thereby assuring a level of profitability, everything being equal.
Answer:
13.0
Explanation:
The method doubleVal() is created to accept a single parameter of type double.
It multiplies what ever the value of the parameter is and returns the resulting value.
In this question The method is called within this output statement System.out.println(doubleVal(val)); (Note that val had already been declared and assigned the value of 6.5)
The value 6.5 is doubled and outputed to the screen
In the game the Vikings speak icelandic
