Batman, wolverine and captain america have been chosen to protect the world from villains. batman and wolverine go and find ammunition. batman finds 75 boxes, whereas wolverine finds 45 boxes. they split the boxes equally and captain america gives them $1400. how much money did batman and wolverine get from the sum, considering having split the boxes up equally?

This is the concept of ratios and approximation; We are required to calculate for the amount of money that Batman and Wolverine got after they split $1400 between them; 
N/B batman found 75 boxes while Wolverine found 45 boxes 
Suppose that the money was divided according to the ratio of the boxes they found.
The ratio of boxes  Batman found to that of Wolverine is:
45/75=3/5
This implies that Batman got 3/5 of the boxes while Wolverine got 2/5

thus the amount of cash Batman got was:
3/5*1400
=$840
The amount Wolverine got was:
1400-840
=$560

To find the contrapositive of a conditional statement we first swap the hypothesis and conclusion, and then negate both. Doing so in this case gives us D.