Problema Solution
You inherited $16,000 from a favorite aunt. You want to invest some of the money but not necessarily all of it in two different accounts. One pays 5% interest the other pays 6% interest. The combined total interest must be at least $860. Write the system of inequalities for this situation. Graph the inequalities and find 2 ways that you could divide the money and make the interest that you want to make.
Answer provided by our tutors
let
x = the money invested at 5% interest, x>0
y = the money invested at 6% interest, y>0
x + y <= 16000
the combined total interest must be at least $860
0.05x + 0.06y => 860
the system of inequalities for this situation:
x >= 0
y >= 0
x + y <= 16000
0.05x + 0.06y => 860
click here to see the graph
First way to divide the money is
x = $2000
y = $14000
and indeed:
2000 + 14000 = 16000
0.05*2000 + 0.06*14000 = 940 > 860
Second way to divide the money is
x = $4000
y = $12000
and indeed:
4000 + 12000 = 16000
0.05*4000 + 0.06*12000 = 920 > 860