The possibility is 3/10 aka 3 over 10 i am very sure this is the answer but i might be wrong i have before
Wouldnt u add all those amounts of money then divide it by 40 so it would give u the amount of money needed to cover her costs?
First Let we solve the Original system of equations:
equation (1): 
equation (2): 
Multiplying equation (1) by 7, we get


Subtracting,
implies 
Then
Thus the solution of the original equation is
Now Let we form the new equation:
Equation 2 is kept unchanged:
Equation (2):
Equation 1 is replaced with the sum of equation 1 and a multiple of equation 2:
Equation (1): 
Now solve this two equations: 
Multiply (1) by 7 and (2) by 8,


Subtracting,
implies 
Then x=2.
so the solution for the new system of equation is x=2, y=1.
This Show that the solution to the system of equations 8x − 5y = 11 and 7x − 8y = 6 is the same as the solution to the given system of equations
<u><em>The answer 5 because you would divide 7 by 1.4 or 7/1.4 and you would get the answer 5.</em></u>
<u><em>Hope This Helps!</em></u>
:)