Answer:
60
Step-by-step explanation:
7x+30+9x+42=104
16x+72=104
16x=104-72
16x=32
x=2
SO:
<BOC=9x+42=
9(2)+42=
18+42=
Bank A will exchange it
Step-by-step example
x>3
12/20 = 0.6
0.6x100=60%