A container has 40 liters of milk. 4 liters are taken out and replaced with…
2024
A container has 40 liters of milk. 4 liters are taken out and replaced with water. This process is repeated two more times. How much milk is in the container now?
- A.
26.34
- B.
29.16
- C.
28.34
- D.
29.18
Attempted by 15 students.
Show answer & explanation
Correct answer: B
Solution:
Start with 40 L of pure milk. Each time 4 L are removed and replaced with water, so the fraction of milk that remains after each operation is 1 - 4/40 = 0.9.
After 1st operation: milk = 40 × 0.9 = 36.0 L.
After 2nd operation: milk = 36.0 × 0.9 = 32.4 L.
After 3rd operation: milk = 32.4 × 0.9 = 29.16 L.
Using the formula for repeated multiplicative change:
Milk = 40 × (1 - 4/40)^3 = 40 × (0.9)^3 = 29.16 L.
Answer: 29.16 liters.