On The First Year, Two Cows Produced 8100 Liters Of Milk. On…

On the first year, two cows produced 8100 liters of milk. On the second year, their production increased by 15% and 10% respectively, and the total amount of milk increased to 9100 liters a year. How many liters of milk from each cow in each year? ​

Answer:

Step-by-step explanation:

Let:

x = liters of milk produced by the first cow

y = liters of milk produced by the second cow

let’s convert percentage values to decimal

10% = 0.1

15% = 0.15

Solution:

On the first year,

x + y = 8100  <=== equation 1

On the second year

(x + 0.1x) + ( y + 0.15y) = 9100

1.1x + 1.15y = 9100 <=== equation 2

Two equations and two unknowns. Solving for x and y using substitution method;

from equation 1

x + y = 8100

y = 8100 -x <=== equation 3

susbstitute equation 3 in equation 2

1.1x + 1.15y = 9100

1.1x + 1.15(8100 – x) = 9100

1.1x + 1.15(8100) – 1.15x = 9100

-0.05x + 9315 = 9100

0.05x = 215

x = 215/0.05

x = 4300 answer

y = 8100 – x = 8100 – 4300 = 3800 answer

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