Multiple choice

A jar was full with Milk. A person used to draw out 20% of the Milk from the jar and replaced it with water. He has repeated the same process 4 times and thus there was only 512 gm of milk left in the jar, the rest part of the jar was filled with the water. The initial amount of milk in the jar was:

  1. 1.50 kg

  2. 1.30 kg

  3. 1.40 kg

  4. 1.25 kg

  5. 1.75 kg
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Formula for remaining amount: A = P(1 - r/100)^n. Here, A = 512, r = 20, n = 4. 512 = P(1 - 0.2)^4 = P(0.8)^4 = P(0.4096). P = 512 / 0.4096 = 1250 grams = 1.25 kg.

AI explanation

Let the initial amount of milk in the jar be M grams, and since 20% is replaced with water four times, the remaining amount of milk is given by the formula M times (1 minus 0.20) to the power of 4. This simplifies to M times 0.8 to the power of 4, which equals M times 0.4096. Setting this equal to the 512 grams left in the jar gives 0.4096M = 512, so dividing yields M = 1250 grams, or 1.25 kg.

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