The answer will be a because they are similar and by law the ratio can be cubed to find ratio of volume
Let e be the amount of 1.35 beans and c be the amount of 1.05 beans...
(1.35e+1.05c)/120=1.15 we know e+c=120, so e=120-c making the equation:
(1.35(120-c)+1.05c)/120=1.15
(162-1.35c+1.05c)/120=1.15
162-0.3c=138
-0.3c=-24
c=80, and since e=120-c, e=40 so:
80 lb of the $1.05 beans are mixed with 40 lb of the $1.35 beans to produce a 120 lb mixture worth $1.15 per pound.
53.2
40%=.4
.4 times 38 = 15.2
15.2+38=53.2
Thank me later