A container contains 100 litres of apple juice. From this container, 10 litres of apple juice was taken out and replaced by equal amount of water. This process was further repeated twice. How much apple juice is left in the container?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 72.9 litres
The process is done 3 times in all (once, then repeated twice). Each time 10 of the 100 litres are replaced, so the juice left is multiplied by \( 1-\frac{10}{100}=0.9 \):
\( \displaystyle 100\times(0.9)^3=100\times 0.729 \)
\( \displaystyle =72.9\ \text{litres} \)
CBSE Applied Mathematics (Class XII):
Alligation and Mixture
