SOLUTION: A man borrowed $950. Six months later, he repaid the loan (principal and interest) with $1150. What simple interest rate did he pay? (Round your final answer to two decimal places.

Algebra ->  Finite-and-infinite-sets -> SOLUTION: A man borrowed $950. Six months later, he repaid the loan (principal and interest) with $1150. What simple interest rate did he pay? (Round your final answer to two decimal places.      Log On


   

Question 1148486: A man borrowed $950. Six months later, he repaid the loan (principal and interest) with $1150. What simple interest rate did he pay? (Round your final answer to two decimal places.)
Found 2 solutions by ikleyn, josmiceli:
Answer by ikleyn(52835) About Me  (Show Source):
You can put this solution on YOUR website!
.

1150 = 950 + 950*r*0.5


1150-950 = 950*r*0.5


200 = 950*r*0.5


r = 200%2F%28950%2A0.5%29 = 0.421 = 42.1%  annual percentage rate simple interest (aproximately).

In my solution, 0.5 = 0.5 of an year = 6 months.



Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+I+=+P%2Ar%2At+
+P+%2B+I+=+1150+
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+950+%2B+I+=+1150+
+I+=+1150+-+950+
+I+=+200+
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+I+=+P%2Ar%2At+
+200+=+950%2Ar%2A%281%2F2%29+
I assume it's annual interest, so I used +t+=+1%2F2+
which is 6 months
+400+=+950r+
+r+=+.4211+
42.11%
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