Answer:
c
Explanation:
The biggest advantage of smartphones and tablets is that they increased the mobility. This allowed users to access the social media platforms whenever they want. The users can login to their accounts even they are travelling by bus or walking around. This was not possible back in the days where people mostly use desktop computers.
<em>r = 15 cm</em>
<em>formula</em>
<em>V = πr²×h/3</em>
<em>replace</em>
<em>4950 = 22/7×r²×21/3</em>
<em>4950 = 22/7×r²×7</em>
<em>4950 = 22×r²</em>
<em>r² = 4950/22</em>
<em>r² = 225</em>
<em>r = √225</em>
<em>r = √15²</em>
<em>r = 15 cm</em>
<span>Not a valid IPv6 address
A valid IPv6 address consist of 8 groups of 4 hexadecimal numbers separated by colons ":". But that can make for a rather long address of 39 characters. So you're allowed to abbreviate an IPv6 address by getting rid of superfluous zeros. The superfluous zeros are leading zeros in each group of 4 digits, but you have to leave at least one digit in each group. The final elimination of 1 or more groups of all zeros is to use a double colon "::" to replace one or more groups of all zeros. But you can only do that once. Otherwise, it results in an ambiguous IP address. For the example of 2001:1d5::30a::1, there are two such omissions, meaning that the address can be any of
2001:1d5:0:30a:0:0:0:1
2001:1d5:0:0:30a:0:0:1
2001:1d5:0:0:0:30a:0:1
And since you can't determine which it is, it's not a valid IP address.</span>
