Multiple choice

In a mixture of 45 liters, the ratio of chemical and water is 5:4. How much chemical must be added to make the ratio of 3:2?

  1. 8

  2. 6

  3. 10

  4. 5

  5. 12
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Initial: Chemical = 5/9 * 45 = 25, Water = 4/9 * 45 = 20. Let x be added chemical: (25+x)/20 = 3/2. 50 + 2x = 60, so 2x = 10, x = 5.

AI explanation

In the initial 45 liters of mixture, the chemical and water quantities are found by dividing 45 by the sum of the ratio parts (5 plus 4 equals 9), resulting in 25 liters of chemical and 20 liters of water. By adding a certain amount of chemical, the new ratio of chemical to water must become 3 to 2. Keeping the water amount at 20 liters, the required chemical amount for this ratio is 20 multiplied by 3 and divided by 2, yielding 30 liters. Since the mixture already contains 25 liters of chemical, you must add 5 liters to reach the required 30 liters.

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