GCSE Maths Practice: standard-form

\( \begin{array}{l}\text{A bacteria population starts at } 3.5 \times 10^4. \\ \text{It doubles every hour. Find the population after 3 hours in standard form.}\end{array} \)

Choose one option:

\( 2.8 \times 10^5 \) \( 1.05 \times 10^5 \) \( 7.0 \times 10^4 \)