I need help with #3 and #1

1) v = (30 cm)/(0.03 s) = 1000 cm/s = 10m/s

3) The driver is lying. The witness said that the accident happened in a blink of an eye and if the driver was really going at 10 km/hr, he would have only traveled 0.83 m out of the parking lot

Option D is correct.

System of equations can be used is given by:

Step-by-step explanation:

here, h represents the weight of the hardcover book, and p represents the weight of the paperback.

As per the given statement: The hardcover version of a book weighs twice as much as its paperback version.

⇒

Also, it is given that the hardcover book and the paperback together weigh 4.2 pounds

⇒

or

Therefore, the system of equations can be used is given by: