Answer:
Step-by-step explanation:
Let m represent the mass of the tea
Let c represent its cost
The cost of tea varies directly with the mass is written as
where k is the constant of proportionality
when m = 4.5kg
c = $ 10.35
Substitute the values into the above formula
10.35 = 4.5k
Divide both sides by 4.5
k = 2.3
So the formula for the problem is
when the mass is 12kg
the cost is
c = 2.3 × 12
Hope this helps you