Two alcohol-water mixtures A and B of ratio 5 ∶ 1 and 5 ∶ 2 respectively are mixed together in the ratio 3 ∶ 4. On adding 2 ml of alcohol to this mixture, 100 ml of final alcohol-water mixture is obtained. What is the percentage of alcohol in the final mixture?
Two alcohol-water mixtures A and B of ratio 5 ∶ 1 and 5 ∶ 2 respectively are mixed together in the ratio 3 ∶ 4. On adding 2 ml of alcohol to this mixture, 100 ml of final alcohol-water mixture is obtained. What is the percentage of alcohol in the final mixture? Correct Answer 77%
Given:
Alcohol : Water in A = 5 : 1.
Alcohol : Water in B = 5 : 2.
Concept used:
We will be using the concept of ratio.
Calculation:
Quantity of mixture before adding 2 ml alcohol = 100 – 2 = 98 ml
Quantity of mixture A mixed = 3/7 × 98 = 42 ml
∵ Ratio of mixture A = 5 ∶ 1
⇒ Quantity of alcohol in 42 ml of mixture A = 5/6 × 42 = 35 ml
Similarly,
Quantity of mixture B mixed = 4/7 × 98 = 56 ml
∵ Ratio of mixture B = 5 ∶ 2
⇒ Quantity of alcohol in 56 ml of mixture B = 5/7 × 56 = 40 ml
⇒ Quantity of alcohol in 100 ml of final mixture = 35 + 40 + 2 = 77 ml
∴ Percentage of alcohol in final mixture = 77/100 × 100 = 77%