We invested a total of $1,000. We invested one part of the money at 3% and the rest of the money at 6%. The total investment with interest at the end of the year was $1,052.50. How much money did we invest at 3%? Answers:
A) $160
B) $190
C) $220
D) $250
E) $280
Let x be the money invested at 3%.   1.03x+1.06(1000-x)=1052.50.   0.03x=1060-1052.50.   0.03x=7.50.   3x=750.   x=250.   The answer is $250.
<result>D</result>
We invested a total of $1,000. We invested one part of the money at 3% and the rest of the money at 6%. The total investment with interest at the end of the year was $1,052.50. How much money did we invest at 3%?