Answer:
32.5% sugar
Explanation:
You want to know the sugar concentration in the mix of two 250-mL cans of soft drink, one of which is 20% sugar, and the other of which is 45% sugar.
Weighted average
The fraction of sugar in the mix is the weighted average of the fractions in the contributors. The weights are the volumes. Since the volumes are equal, the weights are equal, so the fraction in the final mix is simply the average of the two fractions:
(20% +45%)/2 = 65%/2 = 32.5%
The sugar concentration of the mixed soft drink is 32.5%.