Question

A hospital needs 100l of a 15% solution of disinfectant. How many liters of 40% solution and 5% solution should be mixed with

Answer 1

Answer:

200/7 litres of 40% solution and 500/7 of 5% solution

Step-by-step explanation:

Let x and (100l-x) represent the 40% and 5% solutions respectively.

Mixing the 40% and 5%  to form 100l of 15% solution

0.40x + 0.05(100-x) = 0.15 * 100

0.35x = 100(0.15 - 0.05)

0.35x = 10

=> x = 10/35 = 200/7

40% solution = 200/7 litres.

5% solution = 100 - 200/7 = 500/7 litres.

Thus 200/7 litres of 40% solution and 500/7 of 5% solution