Answer:
[tex]\large \boxed{r =\dfrac{\text{RBC}}{\text{WBC}};\,\text{400 times}}[/tex]
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
[tex]\mathbf{r} =\mathbf{ \dfrac{\text{RBC}}{\text{WBC}}}[/tex]
Insert the values and do the division.
[tex]\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.}[/tex]