Question

A 0.25 mL sample of water drawn from a 5 liter flask contains 1.25 x 10^8 bacteria. Give the approximate number of bacteria in the flask, expressing your answer in scientific notation.
(Scientific Notation: find a real number a between 1 and 10, and an integer n, such that x = a x 10^n.)

Answer 1

Answer:

The number of bacteria in 0.25 mL is 6.25 x 10^3.

Step-by-step explanation:

5 liter flask contains 1.25 x 10^8 bacteria.

So, 1liter flask contains = $\frac{1.25 \times 10^8}{5} =2.5\times 10^7$

Now

0.25 mL contains = $2.5\times 10^7 \times0.25\times 10^{-3} = 6.25\times 10^3$