Question
A solution contains 30% alcohol and the rest water. If
there are 20 litres of this solution, how many litres of water must be added to make the alcohol 20% in the new mixture?Solution
Alcohol in original solution = 30% of 20 = 0.30 × 20 = 6 litres Let x litres of water be added. Total volume = 20 + x litres Alcohol remains 6 litres We want alcohol to be 20% of new mixture: 6 = 20% of (20 + x) 6 = (20/100) × (20 + x) 6 = (1/5)(20 + x) Multiply by 5: 30 = 20 + x x = 10 litres Answer: 10 litres of water
More Mixture Questions
- What will come in place of the question mark (?) in the following questions?
300−40% of 200=? - Simplify the following expression:
16 + [17 - (8 + 11) + 6 - 3] ÷ 0.2 Simplify the following expression.
(3-3 × 3 + 3 ÷ 3 + 3 × 5) × 2 of 5 + (2 + 2 ÷ 2 + 2 × 2 - 2)
2/9 of 5/8 of 3/25 of ? = 40
115 ÷ 23 + 12 × 6 = ? + 16 - 35
√? = 32% of 900 + 48% of 50
 Â
5/13 × 104 + 1(2/9) × 198 = 133 + ?
Simplify the following expressions and choose the correct option.
40% of 360 + 25% of 248 - 30
(11/12) × (18/22) × (4/3) + 3 = ?2
[(15)³ × (8)²] ÷ (90 × 6) = ?²
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