I believe it is A. Hope this helps.
Let X is the random number Erik thinks of, and Y is the random number Nita thinks of.
Both X and Y are in the range from 0 to 20.
<span>X<=20
Y<=20
If the difference between their two numbers is less than 10, then Erik wins.
The difference between the two numbers can be written X-Y, or Y-X depending on which number (X or Y) is greater. But we do not know that. In order not to get negative value, we calculate absolute value of X-Y, written |X-Y| which will give positive value whether X is greater than Y or not.
If |X-Y|<10 Erik wins.
</span><span>If the difference between their two numbers is greater than 10, then Nita wins.
</span><span>If |X-Y|>10 Nita Wins
</span>
I got 132 for the area of this shape
