Question

PLEASE PLEASE HELP

Connor needs 60 mL of a 19% acid solution for a science experiment. He has available a 21% solution and a 15% solution.
How many milliliters of the 21% solution and how many milliliters of the 15% solution should he mix to make the 19%
solution?

Answer 1

Let x = ml of 21% solution

Let y = ml of 15% solution

ATQ,

x + y = 60.....(1)

or

0.21x + 0.15y = 0.6....(2)

Multiplying equation 1st by 0.21, we get,

0.21y+0.21y =12.6....(3)

subtracting equation 3

0.21y+0.21y =12.6

-0.21x +0.15y = 0.6

_________________

ㅤㅤㅤ 0.6y = 12

_________________

6y = 12

y = 20ml

x= 60-20 = 40 ml

Hence , Conner needs 20ml of 21% solution & 40ml of 15% solution