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How much pure alcohol has to be added to 400 ml of a solution containing 15% of alcohol to change the concentration of alcohol in the mixture to 32% ?
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- 60 ml
- 100 ml
- 128 ml
- 68 ml
Correct Option: B
According to question ,
| Alcohol = |  | × 400 |  | ml = 60 ml. | 100 |
Water = 400 - 60 = 340 ml.
Let m ml of alcohol be added.
| Then, | × 100 = 32 | 400 + m |
| ⇒ | = | = | |||
| 400 + m | 100 | 25 |
⇒ 1500 + 25m = 3200 + 8m
⇒ 17m = 1700
⇒ m = 100 ml
