Question

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

blood cells. About how many times as great is the number of rea blood cells than the
number of white blood cells? Write and solve an equation.

Answer 1

`\large \boxed{r =\frac{\text{RBC}}{\text{WBC}};\,\text{400 times}}`

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{ \frac{\text{RBC}}{\text{WBC}}}`

Insert the values and do the division.

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