A merchant gains or loses, in a bargain, a certain sum. In a second bargain, he gains 550 dollars, and, in a third, loses 120. In the end he finds he has gained 300 dollars, by the three together. How much did he gain or lose bv the first ?  Pick one:
A) -130  B) 120  C) 130  D) -80  E) None
In this sum, as the profit and loss are opposite in their nature, they must be distinguished by contrary signs. If the profit is marked +, the loss must be -.   Let x = the sum required.   Then according to the statement x + 550 - 120 = 300   And x = -130.   -130nswer -130
<result>A</result>
A merchant gains or loses, in a bargain, a certain sum. In a second bargain, he gains 550 dollars, and, in a third, loses 120. In the end he finds he has gained 300 dollars, by the three together. How much did he gain or lose bv the first ?