Question 1200867
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The response from the other tutor shows a solution using the standard formal algebraic method.<br>
Here is an informal method that can be used to solve any 2-part "mixture" problem like this.  This method is fast and easy, especially if the numbers are "nice".<br>
Php1470 interest on Php20,000 is an interest rate of 1470/20000 = 0.0735 = 7.35%.<br>
The ratio in which the total was split between the two investments is exactly determined by where that 7.35% interest rate lies between the individual interest rates of 6% and 10%.<br>
So look at the three percentages 6, 7.35, and 10 (on a number line, if it helps), and observe/calculate that the 7.35% interest rate is 1.35/4 = 135/400 = 27/80 of the way from 6% to 10%.<br>
That means 27/80 of the total was invested at the higher rate.<br>
20000*(27/80) = 27*(20000/80) = 27*250 = 6750<br>
ANSWERS: Php6750 was invested at 10%; the other Php13250 was invested at 6%<br>
CHECK: .10(6750)+.60(13250) = 675+795 = 1470<br>