Question

1. Scientific Notation and Percent. (Based on the ideas in Objective 1 and Objective 4.) 6 points

Answer 1

Answer: $1.715*10^{12}$ skin cells were not burned.

Step-by-step explanation:

The complete exercise is: Two percent of Sennie's skin cells were burned when she escaped from a fire. If $3.5*10^{10}$ of her skin cells were burned then, how many skin cells were not burned?​

Let be "x" the number of Sennie's skin cells that were not burned when she escaped from the fire.

According the the data given in the exercise, you know that 2% represents $3.5*10^{10}$ of Sennie's skin cells that were burned. This means that the percent of her skin cells that were not burned is:

$100\%-2\%=98\%$

With this information you can write the following proportion:

$\frac{3.5*10^{10}}{2}=\frac{x}{98}$

Solving for "x", you get:

$(98)(\frac{3.5*10^{10}}{2})=x\\\\x=171.5*10^{10}$

To express the result in Scientific notation, the decimal point must be after the first digit; then you must  move the decimal point two places to the left:

$x=1.715*10^{12}$