Problema Solution

A nurse is told to give a patient recovering from surgery a total of 21 units of a potent antibiotic over 3 days. The dosage should be cut in half the second day, then in half again for the third day. How many units should she administer on the first day ?

Answer provided by our tutors

Let

x be the number of units given the first day then

x/2 are the number of units given the second day

(x/2)/2 = x/4 are the number of units given the third day

x + x/2 + x/4 = 21

........

click here to see the equation solved for x

........

x = 12 units

The nurse should administer 12 units on the first day.