An infant ibuprofen suspension contains 100 mg/5.0ml suspension. the recommended dose is 10 mg/kg body weight. how many milliliters of this suspension should be given to an infant weighing 25 lb ?

First, we convert the weight of the infant to kg. 
                                 25 lb x (1 kg / 2.21 lb) = 11.31 kg
Then, we use the givens above for our dimensional analysis. 
                                   (11.31 kg)(10 mg/1 kg)(5.0 mL/100 mg) = 5.655 mL
Thus, the recommended amount in mL of the suspension should be 5.655 or approximately 5.7. 

I’m not sure what your trying to say here.. can you clarify again?