Question

In the lab, Kira has two solutions that contain alcohol and is mixing them with each other. She uses 200 milliliters less of Solution A that Solution B. Solution A is 10% alcohol and Solution B is 20% alcohol. How many milliliters of Solution B does she use, if the resulting mixture has 340 milliliters of pure alcohol?

Answer 1

Answer:

Kira use 1200 ml of solution B.

Step-by-step explanation:

Given:

Two solution with percentage of alcohol.

Percentage of alcohol in solution A =$10\%$ = $0.1$

Percentage of alcohol in solution B = $20\%$ = $0.2$

Quantity of pure alcohol, in (A+B) mix = $340$  ml

According to the question:

Kira uses $200$ milliliters less of Solution A that Solution B.

So,

⇒ $A= B -200$             ...equation (i)

In terms of total quantity and percentage we can re-write it as,

⇒ $0.1A + 0.2B=340$    ...equation (ii)

Substituting the value of A from equation (i) in equation (ii).

⇒ $0.1(B-200)+0.2B=340$

⇒ $0.1B-20+0.2B=340$

⇒  $0.1B+0.2B-20=340$

⇒ $0.3B-20=340$

⇒ $0.3B-20+20=340+20$  ...adding 20 both sides

⇒ $0.3B=360$

⇒ $B=\frac{360}{0.3}$                             ...dividing 0.3 on both sides  

⇒ $B=1200$ ml

She uses 1200 milliliters of solution B where the resulting mixture has 340 ml of pure solutions.