Question

a person preparing medicine wants to convert 15% alcohol solution into 32 percent alcohol solution find how much pure alcohol should be mixed with 400 ml of 15% alcohol solution to obtain it

Answer 1

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

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.