Question 824913
You did not show which money units, but no matter which you have, think of this like a mixture problem in which CONCENTRATION is in units of MONEY UNITS per POUND.


Assign Variables:
L=4.25
T=4.40
H=4.50
M=30 pounds
u = how much pounds of the L
v = how much pounds of the H
Note that T is the target value.


{{{(Lu+Hv)/M=T}}} and {{{u+v=M}}}


This is just like the Mixture lesson linked in my profile.