Question

A 0.1 mm3^3​3​​ sample of human blood has approximately 6000 red blood cells. An adult typically has 5.0 L of blood. How many red blood cells are in an adult? (1 mL = 1 cc). Use "E" for scientific notation.

Answer 1

If 0.1 mm volume blood sample contains 6000 or 6E3 blood cells, then 1 cubic cm of blood contains 6E3 x 10E3 = 6E6 blood cells. One cubic liter of blood is 1000E3 or 1E6 cubic cm. Then 5 L of blood contains 5 x 1E6 x 6E6 = 30E12 or 3E13 blood cells.

Answer 2

3.0 × 10¹¹ RBC's (or) 3E11 RBC's

Solution:

Step 1: Convert mm³ into L;

As,

1 mm³ = 1.0 × 10⁻⁶ Liters

So,

0.1 mm³ = X Liters

Solving for X,

X = (0.1 mm³ × 1.0 × 10⁻⁶ Liters) ÷ 1 mm³

X = 1.0 × 10⁻⁷ Liters

Step 2: Calculate No. of RBC's in 5 Liter Blood:

As given

1.0 × 10⁻⁷ Liters Blood contains = 6000 RBC's

So,

5.0 Liters of Blood will contain = X RBC's

Solving for X,

X = (5.0 Liters × 6000 RBC's) ÷ 1.0 × 10⁻⁷ Liters

X = 3.0 × 10¹¹ RBC's

Or,

X = 3E11 RBC's