B because there is only one negative and -63 divided by 7 equals -9. If it were -7 divided by 63 that would give you an answer in decimal form.
1/6 of an hour is 10 minutes. For a precise answer, convert it to seconds. You will end up with 600 seconds. Divide the area of the sheet by 600 seconds.
1260/600 ~ 2
With this result, Samantha glued approximately 2 stickers every second.