3. Shoji invested 7000, part at 9 % interest and part at 6 % interest. The interest obtained from the 6 % investment was half of the interest obtained from the 9 % investment. How much was invested at each rate?

Question

3. Shoji invested  7000, part at 9 % interest and part at 6 % interest. The interest obtained from the 6 % investment was half of the interest obtained from the 9 % investment. How much was invested at each rate?

Accepted Answer

Step:1 ：Let the amount invested at 9% be (x) and the amount invested at 6% be (y).Step:2 ：Set up the system of equations: [begin{cases} x + y = 7000  0.06y = 0.5(0.09x) end{cases}]Step:3 ：Solve the system of equations to find the values of (x) and (y).Step:4 ：(x = 4000) and (y = 3000)Step:5 ：(boxed{text{Shoji invested 4000 at 9% interest and 3000 at 6% interest.}})

Answer

Step: 1 ：Let the amount invested at 9% be (x) and the amount invested at 6% be (y).Step: 2 ：Set up the system of equations: [begin{cases} x + y = 7000  0.06y = 0.5(0.09x) end{cases}]Step: 3 ：Solve the system of equations to find the values of (x) and (y).Step: 4 ：(x = 4000) and (y = 3000)Step: 5 ：(boxed{text{Shoji invested 4000 at 9% interest and 3000 at 6% interest.}})

3. Shoji invested $\$ 7000$, part at $9 \%$ interest and part at $6 \%$ interest. The interest obtained from the $6 \%$ investment was half of the interest obtained from the $9 \%$ investment. How much was invested at each rate?

Answer

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