Question

Going to send double a pic of

Answer 1

Rounding to three significant figures

`\text{ 3.85 x 10}^(-9)`

done

To round to significant figures, just consider the numbers before the decimal point (3) , and consider all the numbers different from zero after the decimal point (85).

The three significant figures are 3, 8 and 5.

The numbers x 10^-9 are not consider as significant figures.