400 g of apple vinegar has 40% apple juice in it. The amount of apple juice, which should be added to make it 60% in apple vinegar, is:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 200 g **
Amount of mixture = 400 g
Apple-juice content = $40\%$
Apple juice present initially:
$\displaystyle 0.40 \times 400 = 160\ \text{g}$
Let $x$ g of pure apple juice be added.
New total apple juice = $160 + x$
New total mixture = $400 + x$
Required concentration = $60\%$
$\displaystyle \frac{160 + x}{400 + x} = \frac{3}{5}$
Cross-multiply:
$5(160 + x) = 3(400 + x)$
$800 + 5x = 1200 + 3x$
$2x = 400$
$x = 200$
Amount of apple juice to be added = 200 g