Answer:
231 ml
Explanation:
Let x represent the amo unt of Dextrose 70% in ml and y represent the amount of Dextrose 5% in ml needed to prepare 1,000mL of Dextrose 20%.
Since 1000 ml of Dextrose 20% is needed, hence:
x + y = 1000 (1)
Also 70% Dextrose is mixed with 5% dextrose to produce 20% dextrose. i.e.:
70% of x + 5% of y = 20% of 1000
0.7x + 0.05y = 200 (2)
We have to solve equations 1 and 2 simultaneously.
Let us multiply equation 2 by 20:
14x + y = 4000 (3)
subtract equation 1 from 3:
13x = 3000
x = 231 ml
Put x = 231 in equation 1 to find y:
231 + y = 1000
y = 769 ml
Therefore 231 ml of Dextrose 70% must be mixed with 769 ml of Dextrose 5% to prepare 1,000mL of Dextrose 20%? *