Question 1199654
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Here is an quick and easy informal method for solving any 2-part "mixture" problem like this.<br>
(1) All $800 invested at 2% would earn $16 interest; all at 7% would earn $56 interest.
(2) The actual interest, $26, was 10/40 = 1/4 of the way from $16 to $56.  ($16 to $56 is a difference of 40; $16 to $26 is a difference of 10; 10/40 = 1/4.)
(3) That means 1/4 of the total was invested at the higher rate.<br>
1/4 of $800 is $200; so<br>
ANSWERS: $200 was invested at 7% and the other $600 at 2%.<br>
CHECK: .07(200)+.02(600) = 14+12 = 26<br>