Question

The average adult human has approximately 2.5 X 10' red blood cells and 7 X 10' white

Answer 1

Answer:

$\large \boxed{r =\dfrac{\text{RBC}}{\text{WBC}};\,\text{400 times}}$

Step-by-step explanation:

I think your missing numbers are

RBC = 2.5 × 10¹³ and  

WBC = 7    × 10¹⁰

This is a ratio question.

You are asked to find the ratio of RBCs to WBCs.

Let r = the ratio.

Then the equation for the ratio is

$\mathbf{r} =\mathbf{ \dfrac{\text{RBC}}{\text{WBC}}}$

Insert the values and do the division.

$\begin{array}{rcl}r& =& \dfrac{\text{RBC}}{\text{WBC}}\\\\& =&\dfrac{2.5 \times 10^{13}}{7 \times 10^{10}}\\\\& =&\mathbf{400}\\\end{array}\\\text{The number of RBCs is \large \boxed{\textbf{400 times}} as great as that of the WBCs.}$