Question

Linda invests $6500 in a Black Sheep Building Society for 2 years. The Building Society pays an interest of 4% on the sum invested each year. How much interest will she receive?

Answer 1

Answer:

Points Z=

100

10

x+

100

9

y

A(20000,10000) Z=Rs.2900

B(40000,10000) Rs.4900 (Maximize)

C(25000,25000) Rs.4750

D(20000,20000) Rs.3800

Let Rs.x invest in bond A and Rs.y invest in bond B.

Then A.T.P.

Maximise, z=

100

10

x+

100

9

y --- (1)

Subject to constraints

x+y≤50,000 --- (a)

x≥20,000---(b)

y≥10,000--- (c)

and x≥y

or x−y≥0--- (d)

and x≥0,y≥0

Now change inequality into equations

x+y=50,000,x=20,000,y=10,000,x=y

Region: put (0, 0) in (a), (b), (c), (d)

0≤50000 (towards origin)

0≥20,000 (away from origin)

0≥10,000 (away from origin)

As shown in the graph.

So from the tabular column, we conclude that he has to invest Rs.40,000 in 'A' and Rs.10,000 in bond 'B' to get maximum return Rs.4,900.