. What is the answer

Question

A human body contains 2.7*10^4 microliters of blood for each pound of body weight. Each microliter of blood contains about 7* 10^4 white blood cells. About how many blood cells are in the body of a 140lb person? 

Answer 1

(1.4 x 10²)(2.7 x 10⁴)(7.0 x 10⁴)

(3.78 x 10⁶)(7.0 x 10⁴)

26.46 x 10¹⁰

2.646 x 10¹¹