The equation to find out what the allowance would be is 2^(n-1), with n being the number of weeks. Thus, for 25 weeks, you would plug in 25 for n and get 2^24, or 16,777,216
To solve these kind of question we just simply keep on inserting the values of x and if we get the required value of y that is in the table that equation is our answer, For example lets take Option A,
y = 8x
If we insert x = 0 we get,
y = 8(0)
y=0
but in the table it says we get 14 so option A is incorrect
Like this we keep checking for more values and all the values of x satisfy our equation in Option B like this,