Answer:
Wakaba bought 18 granola bars and 9 energy drinks.
Explanation:
From the information given, you can write the following equations:
0.50x+2y=27 (1)
x=2y (2),where:
x is the number of granola bars
y is the number of energy drinks
You can replace (2) in (1) and solve for y:
0.50(2y)+2y=27
y+2y=27
3y=27
y=27/3
y=9
Now, you can replace the value of y in (2) to find x:
x=2(9)
x=18
According to this, the answer is that Wakaba bought 18 granola bars and 9 energy drinks.