Question

an amount of 50000 is out into three investments at the rate of 6%, 7%, 8% respectively. the total annual income is 3580. if the combined income from the first two investments is 70 more than the income from the third. find the amount invested in each type of investment separately.

Answer 1

Answer:

here is answer dear friend

Answer 2

Answer:

Let investments be x, y, z.

x=1006×5000=300

y=1007×5000=350

z=1008×5000=400

Now,

6x+7y+8z=100 ………(1)

x+y+z=358 ……(2)

x+y−z=70 ………(3)

Δx=B

⎣⎢⎢⎡61171181−1⎦⎥⎥⎤⎣⎢⎢⎡xyz⎦⎥⎥⎤=⎣⎢⎢⎡10035870⎦⎥⎥⎤

=Δ=∣∣∣∣∣∣∣∣6

=(−6+8+7)−(8+6−7)

=9−7=2

Δ1=∣∣∣∣∣∣∣∣1003587071181−1∣∣∣∣∣∣∣∣

=(−100+358×8+490)−(560+100−7×358)

=−70+15×358

=5300

Δ2=∣∣∣∣∣∣∣∣6111003587081−1∣∣∣∣∣∣∣∣

=(−6×358+100−560)−(8×358+420−100)

=−14×358

=−4672

Δ3=∣∣∣∣∣∣∣∣61171110035870∣∣∣∣∣∣∣∣

=(1420+100+7×358)−(100+6×358+490)

=288

x=ΔΔ1=25300=2650

y=ΔΔ2=2−4672=2336

z=ΔΔ3=2288=144

Amount of each investment is Rs. 2650, Rs. 2336, Rs. 144.