With CIDR (Common Internet Domain Routing), the first decimal number isn't important any more. The /24 netmask means that there's one octet (256) numbers that aren't part of the network number. The .0 address is the network number itself and .255 is the broadcast address of the network, so that leaves 254 available node numbers, but one of those has to be a router or else the machines can't communicate with other networks.
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)
If you’ve ever had a savings account, you likely know that a few cents in interest every month barely adds up. The goal is “compounding returns,” which simply means that the interest you earn each month earns additional interest, which then earns even more interest. But although a savings account will help with that, you may be lucky enough to be able to afford a cup of coffee every 10 years or so at that rate. Instead, it’s important to find a way to invest your money in a high-interest account that will earn compounding returns.
I hope this helps you out ;)
It means it's being spread really quickly all over the world.
