Each machine of type A has 3 steel parts and 2 chrome parts. Each machine of type B has 4 steel parts and 7 chrome parts. If a certain group of type A and type B machines has a total of 20 steel parts and 22 chrome parts , how many machines are in the group?
A.2
B.3
C.4
D.6
E.9![]()
A.2
B.3
C.4
D.6
E.9