Answer:
434444
Step-by-step explanation:
Melanie.
The possible ways of getting a 6 are (3,3), (2,4), (4,2), (1,5) and (5,1).
That is 5 ways.
The possible ways of getting a 7 are (1,6), (6,1), (5,2),( 2,5), (3, 4), (4,3).
That is 6 ways.
So Melanie made the better decision.
241 tons
312-170=142
142÷2=71
170+71=241
241+71=312
train B weighs 241 tons