Chain Rule Practice Test 3 with solutions

Let the two metals be x and y and the cost of the metals is A and B respectively.
Then,
Ax + By = 174 ……(i)
Ay + Bx = 162 ……(ii)
x + y = 24 and A = 8
Substituting these value in equations (i) and (ii),
we get
8(x + y) + B(x + y) = 336
8(24) + B(24) = 336
192 + 24B = 336
24B = 144
B = 6
Price of metal y be Rs 6 per gram.