Question

1. A person preparing medicine wants to convert 15% alcohol solution in 32% alcohol solution. Find how much pure alcohol should be mixed with 400mL of 15% alcohol solution to get it

Answer 1

Answer :

Given : A person preparing a medicine wants to convert 15% alcohol solution into 32% alcohol solution. 

And

In 400 ml of 15% alcohol , So 

Let x = Amount  of alcohol that mix in alcohol solution .

15% of 400  +  x =  32 % of (  400 +  x  )

⇒15 × 400100 + x=32 ×( 400 +x)100⇒60 + x= 12800 + 32x100⇒6000 + 100x= 12800 + 32x⇒100x −32 x= 12800  − 6000⇒ 68 x = 6800 ⇒ x = 6800 68⇒ x =100 
So,

We should mix 100 ml of pure alcohol  to convert 15% alcohol solution into 32% alcohol solution.             ( Ans )

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