Answer:
The ratio between Roberto and David is 3:11
Step-by-step explanation:
If Roberto were to have 18 cards when we start, then David would have 24. Roberto has 3/4 the amount that David has. Then Roberto gives half of his cards (9) to David. Roberto now has 9 cards and David has 33.
If the company makes 50 deliveries in 5 days, he makes 50/5=10 deliveries per day. Therefore, 400 deliveries will take 400/10=40 days. D is the correct answer.
-2. Because on the number line it goes -3 -2 -1 0 1 2 3 so if you count backwards from 2 it is -2