Question

How much Dextrose 70% must be mixed with Dextrose 5% to prepare 1,000mL of Dextrose 20%? *

Answer 1

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%? *