Question

A chemist mixes two liquids 1 and 2. One litre of liquid 1 weighs 1 kg and one litre of liquid 2 weighs 800 gm. If half litre of the mixture weighs 480 gm, then the percentage of liquid 1 in the mixture, in terms of volume, is

• A. 85
• B. 70
• C. 75
• D. 80

Answer 1

Answer: (D)

80

Answer 2

Weight of liquid 1 per liter is 1000 gm, and for liquid 2, it is 800 gm.
The weight of the mixture per liter, obtained by mixing the two liquids = 2×480 gm = 960 gm.
Using the allegation rule,
The ratio of the
Quantity of liquid 1 to liquid 2 is calculated as:
= $\frac{960 - 800}{1000 - 960} = \frac{4}{1}$.
This implies that the liquids are mixed in a ratio of 4:1.
Consequently, the percentage of liquid 1 in the mixture is determined as = $\frac{4}{(4 + 1)} \times 100$, resulting in 80%.