Question

Lab assistant has the solution of 50% acid and other which has 25% acid how much of each should be mixed to make 10 litres of 40% solution

Answer 1

Let 'x' be the amount of 50% acid solution while 'y' be the amount of 25% acid solution.

Now, As Per Question,

x+y=10 ---(1)

or y=10-x ---(2)

Also,

50%= 0.5 and 25%= 0.25 and 40%=0.4

0.5x+0.25y=0.4(10)

=> 0.5x+0.25(10-x)= 4

=> 0.5x+2.5-0.25x= 4

=> 0.25x=4-2.5

=> 0.25x= 1.5

=> x=1.5/0.25

=> x=150/25

=> x=6

Also from (2),

y=10-x or y= 10-6=> y=4

Therefore Required Amount of solutions of acid to make a 40% acid solution will be

For 50%= 6litres

For 25%= 4litres.

Hope it helps!