Multiple choice

In what ratio must a 1 : 1 mixture of whisky and water be mixed with a 3 : 7 mixture to obtain a 2 : 3 mixture?

  1. 2 : 3

  2. 3 : 2

  3. 2 : 1

  4. 1 : 1
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Using the alligation method, the first mixture is 1/2 whisky and the second is 3/10 whisky. The target mixture is 2/5 whisky. The differences are |2/5 - 3/10| = 1/10 and |1/2 - 2/5| = 1/10, resulting in a ratio of 1:1.

AI explanation

Using the rule of alligation, compare the proportion of water in the two mixtures to the proportion in the desired mixture. The first mixture has a water proportion of 1/2, the second has a water proportion of 7/10, and the target mixture has a water proportion of 3/5. The ratio of the quantities of the first to the second mixture is calculated as (7/10 - 3/5) to (3/5 - 1/2). This simplifies to 1/10 to 1/10, making the required mixing ratio 1 : 1.

Keep practicing — related questions