Question

how long would you have to film something in hd to collect 1 pb of data?
all day for 2 consecutive weeks
all day for 365 days (or 364 days in a leap year)
all day for about 3.5 years
all day for one light year

Explanation:

Step1: Know data - rate of HD video

Typical HD video has a data - rate of about 100 Mbps (megabits per second). First, convert 1 PB (petabyte) to megabits. 1 PB = 1024 1024 1024 MB, and since 1 byte = 8 bits, 1 PB = 1024 1024 1024 * 8 Mbits.

Step2: Calculate time

Time $t=\frac{\text{Total data}}{\text{Data - rate}}$. The data - rate $r = 100$ Mbps. So $t=\frac{1024\times1024\times1024\times8}{100}$ seconds.
1 hour has 3600 seconds, 1 day has 24 hours. Calculate the number of days and then years.
$t=\frac{1024\times1024\times1024\times8}{100\times3600\times24}\approx 1277$ days.
1277 days $\div$ 365 days/year $\approx 3.5$ years.

Answer:

all day for about 3.5 years