Generate the vector of even numbers $\text{'}\{2,4,6,$dots,$20\}\text{'}$

a$.$ Using the 'sea $O\text{'}$ function and

b$.$ Using the $\text{'}a$:$b\text{'}$ shortcut and some subsequent algebra. $51$

$52.\{r\}$

$53$ # Insert your code for this question after this line

$54$

$55$

$56$