Question

how much pure alcohol must be added to 400 ml of 15% solution to make its strength 32% A 40 ml B. 120 ml C 100 ml D 150ml ​

Answer 1

Answer:

100 ml

Step-by-step explanation:

given quantity of alcohol in 400 ml solution is 15/100 * 400 =60 ml.

let the pure alcohol added be x , now the solution becomes (400+x)ml and alcohol becomes (60+x)ml , now this (60+x) ml must be 32% of the solution which is (400+x)ml

mathematical equation will be:

(60+x)*100/(400+x) =32

x will come 100 ml

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