The cost of 20 burgers is $30.
Step-by-step explanation:
It is given that, the cost of burgers varies directly with the number of burgers.
This means that, according to the number of burgers purchased, the cost of the burger has been changed.
The cost of the 30 burgers = $45
Let us assume, the cost of the 20 burgers = x
In order to find the value of x, use rate formula :
Rate = Total cost of the burgers / No.of burgers.
⇒ 45/30
Similarly, the cost is x for 20 burgers
⇒ x/20
Comparing the two rates,
⇒ 45/30 = x/20
⇒ x = (45×20) / 30
⇒ x = 900 / 30
⇒ x = 30
Therefore, the cost of 20 burgers is $30.
