To solve the problem we must establish two equations. let x be the mass of the 20 cents almonds y be the mass of the 36 cents mixture first equation is:
x + 40 = y
the second equation is: 0.2x + 40(0.4) = 0.36y
solving the equations simultaneously x = 10 lb of the 20 cents almonds is needed to mix
It is 74 degrees because those two equations equal each other and you must cancel them out which equals x=15. plug 15 in to one of the equations and you have the answer.