Answer: Her weekly allowance is 24 dollars
Step-by-step explanation:
If she is left with $12 spending half of her weekly allowance the we could set up the equation.
1/2 of x = 12 where x is her weekly allowance.
1/2x = 12
x = 24
Total price after 6 years in Account I is :

Total price after 6 years in Account II is :

Total balance, 
Hence, this is the required solution.
Answer: (11/2)π units.
Step-by-step explanation:
I've attached the solution.
Before seeing it there is a theorem you should remember.
The angle subtended by an arc of a circle at its center is twice of the angle it subtends anywhere on the circle’s circumference.