<PRE><B>Question 1035249</B>
if he wants to make 15% overall, then his total profit needs to be 10 * 12000 * .15 = 18000.


he sold 7 at 16% profit.


profit on the 7 was therefore 7 * 12000 * 16/100 = 13440.


the remaining 3 need to earn him 18000 - 13440 = 4560.


you get 3 * x = 4560.


solve for x to get x = 4560 / 3 = 1520.


1520 / 12000 = .1266666.....


multiply that by 100 and you get that he needs to earn 12 and 2/3 % profit on the remaining 3.


you get:


7 * 16 / 100 * 12000 = 13440
3 * (12 + 2/3) / 100 * 12000 = 4560
13440 + 4560 = 18000.


total profit is 18000.
18000 / (10 * 12000) = 18000 / 120000 = .15 = 15%.

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