Final answer:
To determine the percentage strength of alcohol in the given mixture, calculations are made based on the volume of pure alcohol present in the components witch hazel and a 50% alcohol solution. After calculations, the percentage strength is slightly above 40%, which is not among the given options.
Step-by-step explanation:
The question asks for the percentage strength of alcohol in a mixture. To find the percentage strength of alcohol, we need to determine the total volume of pure alcohol in the mixture and then calculate how this relates to the total volume of the mixture.
First, we determine the volume of alcohol in each component. Witch hazel 149 indicates it is 149 proof, which means it contains 74.5% alcohol by volume. For 150 ml of witch hazel, the volume of pure alcohol is 150 ml × 74.5%. The 500ml of 50% alcohol contributes 500 ml × 50% pure alcohol. Glycerin does not contain alcohol, so its contribution is 0.
Adding these amounts up and dividing by the total volume of the mixture (150 ml + 200 ml + 500 ml) gives us the overall percentage strength of alcohol.
Calculation for witch hazel alcohol content: 150 ml × 0.745 = 111.75 ml
Calculation for the 50% alcohol solution: 500 ml × 0.50 = 250 ml
Total alcohol volume: 111.75 ml + 250 ml = 361.75 ml
Total mixture volume: 150 ml + 200 ml + 500 ml = 850 ml
Percentage strength of alcohol: (361.75 ml / 850 ml) × 100 = 42.56%
Thus, none of the options a) 25%, b) 30%, c) 35%, d) 40% are correct. The correct answer would be slightly above 40%, which is not given in the options.