A used-car dealer sold one car at a profit of 25 percent of the dealer's purchase price for that car and sold another car at a loss of 20 percent of the dealer's purchase price for that car. If the dealer sold each car for $20,000, what was the dealer's total profit or loss, in dollars, for the two transactions combined?
$1,000 profit
$2,000 profit
$1,000 loss
$2,000 loss
$3,334 loss
这题不难关键要读懂题意,注意陷阱,他并没有说两辆车购入的价格一样
1.25x=20000
0.8y=20000
设买入车的价格分别是X,Y
那么第一辆车:20000 = x(1 + 25%)x = 16000刀一共赚了:4000刀
那么第二辆车:20000 = y(1-20%)y = 25000刀一共赔了:5000刀
1.25*p = 20000
0.8*q = 20000
profit+less = 0.25*p-0.2*q=4000-5000=-1000
pc1-ps1=25%ps1=pr1
pc2=80%ps2,pc2-ps2=pr2
pc1=pc2=20000
问:pr1+pr2=?
注意陷阱,题目没有说ps1=ps2!!