Each Machine of type A has 4 steel parts and 2 chrome parts. Each machine of type B has 2 steel parts and 1 chrome parts. If a certain group of type A and type B machines has a total of 30 steel parts and 33 chrome parts, how many machines are in the group Options:
A) 12  B) 13  C) 14  D) 16  E) 19

Rationale: "look at the below representation of the problem : steel chrome total a 4 2 30 > > no . of type a machines = 30 / 6 = 5 b 2 1 33 > > no . of type b machines = 33 / 3 = 11 so the answer is 16 i . e d . hope its clear ."
Answer: D