Given :
The concentration of an Furosemide is 40 mg/5 ml.
To Find :
What volume would be required for an 8 mg dose ?
Solution :
Let, volume require for an 8 mg dose is V ml.
It is given that volume of 40 mg Furosemide is 5 ml.
So, volume per gram of Furosemide is :

So, volume required for 8 mg dose is :

Therefore, volume required for an 8 mg dose is 1 ml.