Question

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

Answer 1

Le the alcohol added be x.

Given, 15% of 400 = 60ml.

 Then, (60 + x) / (400 + x) = 32%

            60 + x = (400 + x) (0.32)

            60 + x = 128 + 0.32 x

              0.68 = 68x

                x = 100.


Hope this helps!

Answer 2

Answer:

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