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 4 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?  Choose the most appropriate option:
A) 5:4
B) 7:6
C) 9:8
D) 11:10
E) 13:12
3B = 7C and so B = 7C/3   7A = 4B and so A = 4B/7 = 4C/3   A+B = 4C/3 + 7C/3 = 11C/3   B+C = 7C/3 + C = 10C/3   The ratio of A+B:B+C = 11:10   The answer is 11:10.
<result>D</result>
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 4 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?