Question

1. biology a human body contains about 2.7 × 10⁴ microliters (μl) of blood for each pound of body weight. each microliter of blood contains about 7 × 10⁴ white blood cells. about how many white blood cells are in the body of a 140 - lb person?

Explanation:

Step1: Calculate total microliters of blood

Multiply blood per pound by body - weight.
$2.7\times10^{4}\times140 = 2.7\times10^{4}\times1.4\times10^{2}= (2.7\times1.4)\times10^{4 + 2}=3.78\times10^{6}$ (microliters of blood in 140 - lb person)

Step2: Calculate total white - blood cells

Multiply total microliters of blood by white - blood cells per microliter.
$(3.78\times10^{6})\times(7\times10^{4})=(3.78\times7)\times10^{6 + 4}=26.46\times10^{10}$

Step3: Convert to scientific notation

$26.46\times10^{10}=2.646\times10^{11}$

Answer:

$2.646\times10^{11}$