Question

Question #157eb

Answer 1

Betsy sold 60 and daisy sold 30

Explanation:

Assuming Betsy sells `b` gallons of milk and Daisy sells `d` gallons of milk:

`b + d = 90` because 90 gallons were sold totally

Therefore `b = 90 - d` (Equation 1)

Betsy earns $`4b` because her milk costs $4 a gallon

Daisy earns $`8d` because her milk costs $8 a gallon

Therefore `4b + 8d = 480` (Equation 2)

Now we must use simultaneous equations to arrive find the values of `b` and `d`

Substituting equation 1 into 2,

We get 4(90 - d) + 8d = 480
By solving we get 4d = 480 - 360
Therefore d = `120/4` = 30

Therefore from equation 1,
b = 90 - 30 = 60

Therefore Betsy sold 60 gallons and daisy sold 30.