Question

how much pure alcohol must be added to 400 ml of 15% solution to make its strength 32%

Answer 1

15% of 400 is 60
it means 60ml of solution contains 1% of alcohol
so to make the strength of 32%of alcohol we multiply 60 by, 132
I.e. 60*32=192
therefore 192ml of alcohol should be added to the solution to makes the strength of 32% so
Answer is 192ml

Answer 2

Hi mate,

Solution :

=> Volume of alcohol in 400 ml solution

➾ 0.15 × 400 ml

=> Volume of alcohol in 400 ml solution

➾ 60 ml

=> Volume of others liquid

➾ 340 ml

=> Let x ml of alcohol is added to make it 32% strong

=> Then, volume of alcohol

➾ 60+x ml

=> Volume of other liquid

➾ 340 ml

=> Volume of solution

➾ 400 + x ml

➾ 0.32 × (400 + x) = 60 + x

➾ 128 + 0.32x = 60 + x

➾ 0.68x = 68

➾ 68x = 6800

➾ x = 100 ml ...

Answer : 100 ml pure alcohol must be added to 400ml of a 15% solution to make it's strength 32%

i hope it helps you