<span>There must be an intersection of the arcs so you can connect the vertex of the angle to it</span>
X-x-2/6=x-7/3+2/3
-2/6+7/3-2/3=x
x= -2/6+5/3
x= 8/6
x= 4/3
I would say the correct answer is 1728.
The figures are increasing by half each week. To calculate the figure for the 11th week you could use this sum: 20×1.5^11
20 is the starting figure. 1.5 is the multiplying factor to get the figure for the next week and the 11 is the number of weeks.
I hope this helps.