Page 121 - DMTH201_Basic Mathematics-1

Basic Mathematics – I

Notes
7800 4000 11400 8000 5000 10500 7000 4500 12600

9750 6000 3800 10000 7500 3500 8950 6750 4200

Bang. Bomb. ND
23200 23500 24100 Jain
19550 21000 19900 Gupta
2 3
Jain has to sell his shares in New Delhi and Gupta has to sell his shares in Bombay to get
maximum receipt.

Example: Keerthi buys 8 dozen of pens, 10 dozens of pencils and 4 dozen of rubber. Pens
cost 18 per dozen, pencils 9 per dozen and rubber 6 per dozen. Represent the quantities
bought by a row matrix and prices by a column matrix and hence obtain the total cost.

Solution:
Let A be the row matrix of quantities and B be the column matrix of prices.

A 8 10 4

18
B 9

6

18
AB 8 10 4 9 [144 90 24] [258]
6

Total cost is 258.

Example: Two oil merchants have the following stock of oil (in kg):
Merchant Groundnut Sunflower Coconut
A 250 300 150
B 400 350 100

The approximate prices (in per kg) of three types of oil in 3 markets are:
Market Groundnut Sunflower Coconut
X 70 50 150
Y 60 55 140

Z 55 60 132
In which market each of the above businessmen has to sell his stocks to get maximum receipt?
Solve by matrix multiplication method.

Solution:

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