Answer:
353.6
Step-by-step explanation:
White blood cells in average drop of blood = 1.6 * 104 = 166.4
White blood cels in rare drop of blood = 5 * 104 = 520
Difference between the number of white blood cells in a rare drop of blood and the number of white blood cells in an average drop of blood
= 520 - 166.4 = 353.6