Apharmacy wishes to mix a solution that is 5 minoxidil. she has on hand 60ml of a 4% solution and wishes to add some 7% solution to obtain the desired 5% solution. how much 7% solution should she add

30 ml  of 7% solution should be added.

Step-by-step explanation:

Given:

A solution of 5% minoxidil. On hand is 60ml of a 4% solution and wishes to add some 7% solution to obtain the desired 5% solution.

Now, to get how much 7% solution should be added.

So, we put formula to express concentration as amount of volume of solution:

c = concentration, n = substance.

Thus, the amount of substance is:

Now, in this the total amount of minoxidil is the same before and after mixing as given in question.

So, we can set the equation where V is the volume of the 7% solution:

⇒

Getting the variables one side and the numbers other side we get:

⇒

⇒

Dividing both sides by 2 we get:

⇒

Volume of the solution = 30 ml

Therefore, 30 ml of 7% solution should be added.

7! = 7×6×5×4×3×2

3! = 3× 2

as 7! is multiple of 3! because 7! contains 3! that is 3× 2 as factor

so 7! /(3! ) = 7× 6× 5× 4

= 42 × 20

= 840

its b) 840✌✌✌

dhruv⭐