Question
A container contains 60 liters of a solution containing
25% alcohol. How many liters of pure alcohol must be added to make the alcohol concentration 40%?Solution
Let x liters of pure alcohol be added to the mixture. Initially, the amount of alcohol in the mixture is 25% of 60 liters, which is 15 liters. After adding x liters of pure alcohol, the total amount of alcohol becomes 15 + x liters, and the total volume of the solution becomes 60 + x liters. The final concentration of alcohol is 40%. We can set up the equation: (15 + x) / (60 + x) = 40/100 = 2/5. Cross-multiply: 5 × (15 + x) = 2 × (60 + x), 75 + 5x = 120 + 2x, 5x - 2x = 120 - 75, 3x = 45, x = 45 / 3 = 15 liters. Correct option: c) 15 liters.
47.87% of 749.76 + 35.11% of 399.76 = √? + 23.15 × 20.87
- What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)
(?)2 = (5.99)2 + (7.88)2 + 43.99
Train 'P' travels at a speed of 45 km/h and crosses train 'Q' in 15 seconds while moving in opposite directions. Determine the speed of train 'Q' if the...
`[(7.99)^2 - (13.001)^2 + (4.01)^3]^2=` ?
A number is first increased by 35% and then decreased by 35%. If the net change in the number is 302.5, then find the original number.
A bag contains red, green, and blue balls, with a total of 16 balls. The probability of drawing two blue balls in one draw is 3/8. How many blue balls a...
35.05% of 14.87 × (13.02 – ?) + 30.19 = 188.7
What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)...
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