Multiple choice

A pot contains 50 litres of water. From this container, 5 litres of water is taken out and replaced by milk. This process is applied two more times. How much water is now contained in the pot?

  1. 45 litres

  2. 40.5 litres

  3. 29 litres

  4. 36.45 litres
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Remaining water = 50 * (1 - 5/50)^3 = 50 * (0.9)^3 = 50 * 0.729 = 36.45.

AI explanation

Using the replacement formula for mixtures, the final amount of the original liquid is calculated as Initial Amount multiplied by the fraction remaining after each replacement, raised to the power of the number of operations. The initial amount is 50 litres, and replacing 5 litres means 90 percent (0.9) of the water remains after each of the 3 total operations. The calculation is 50 multiplied by 0.9 cubed (0.729), which results in 36.45 litres of water remaining in the pot.

Keep practicing — related questions