Final answer:
The Tran family purchased 4 packages of hamburger buns and 8 packages of hot-dog buns.
Step-by-step explanation:
The Tran family is bringing 12 packages of buns to the neighborhood picnic. Let's denote the number of hamburger bun packages as x and the number of hot-dog bun packages as y. We can set up a system of equations to represent the information given:
x + y = 12
2x + 1.5y = 20
To solve this system, we can use the method of substitution or elimination. Let's use substitution:
From the first equation, we can express x in terms of y: x = 12 - y. Substituting this into the second equation, we have:
2(12 - y) + 1.5y = 20
Simplifying, we get:
24 - 2y + 1.5y = 20
Combining like terms, we have:
-0.5y = -4
Dividing by -0.5, we find that y = 8. Substituting this back into the first equation, we can solve for x:
x + 8 = 12
x = 4
Therefore, the Tran family purchased 4 packages of hamburger buns and 8 packages of hot-dog buns.