The weight of every type A widget is the same, the weight of every type B widget is the same, and the weight of every type C widget is the same. If the weight of 7 type A widgets is equal to the weight of 2 type B widgets, and the weight of 3 type B widgets is equal to the weight of 7 type C widgets. What is the ratio of the total weight of 1 type A widget and 1 type B widget, to the total weight of 1 type B widget and 1 type C widget?	Pick one:
A) 1 : 2 B) 3 : 4 C) 5 : 6 D) 7 : 8 E) 9 : 10

Rationale: 3 b = 7 c and so b = 7 c / 3 7 a = 2 b and so a = 2 b / 7 = 2 c / 3 a + b = 2 c / 3 + 7 c / 3 = 9 c / 3 b + c = 7 c / 3 + c = 10 c / 3 the ratio of a + b : b + c = 9 : 10 the answer is e .
Answer: E