Answer:
A)
first property= 40,000
2nd property=90,000
3rd property= 80,000
B)
annual income from first property= 4800
annual income from 2nd property= 9000
annual income from third property = 6400
Step-by-step explanation:
So, we can form two equation.
first is, total amount invested in three properties is 210,000
A+B+C=210,000 eq (1)
A is the first property
B is the 2nd property
C is the 3rd property
2nd is, annual income from the property is 20,200
12%*A+10%*B+8%*C= 20,200 eq (2)
As, we have given
the amount invested at 8% is twice that invested at 12%.
it means C is the twice of A
so, the only way we can make A equal to C by multiplying 2 with A, otherwise both won't be equal.
so, 2A=C eq(3)
substituting eq 3 with eq (1) and eq (2)
then we get
A+B+2A=210,000
3A+B=210,000 eq(4)
And,
0.12A+0.10B+0.08*2*A=20,200
0.28A+0.10B=20,200 eq(5)
Finally,
3A+B=210,000
0.28A+0.10B=20,200
multiplying equation (4) with 0.10 then
0.3A+0.10B=21,000
multiplying -1 with equation (5)
-0.28A-0.10B=-20,200
Add them, we get -0.02A=-800
A=40,000
so, putting the value of A in eq (3)
then 2*40,000=C
C=80,000
putting the value of A and B in equation (1)
We get
B=90,000
2nd part of the question
so, income from A is 4800
so, income from B is 9000
so, income from C is 6400