A store purchased 20 coats that each cost an equal amount and then sold each of the 20 coats at an equal price. What was the store’s gross profit on 20 coats?Question: 20*selling price - 20*cost = ? --> 20*(s - c) = ? So basically we are asked to determine the value of s - c.
(1) If the selling price per coat had been twice as much , the store’s gross profit on the 20 coats would have been $2,400 --> 20*2s - 20c = 2,400 --> 2s - c = 120 --> not sufficient to calculate s - c.
(2) If the selling price per coat had been $2 more, the store’s gross profit on the 20 coats would have been $440 --> 20*(s + 2) - 20c = 440 --> 20s + 40 - 20c = 440 --> s - c = 20. Sufficient.
Or you can deal with this statement in another way: increasing the price per coat by $2 will give a store an additional 20*2$=$40, so the profit without this increase should be 440-40=$400. Sufficient.
Answer: B.