There is a 1 in four chance of rolling those 3 numbers. You know this because there is a 3/12 chance of of rolling a 10,11, or 12. Simplify the fraction and you get 1/4.
You need to find the perimeter so your units would be feet.
LETTER B
Coefficient of variation is the ratio of the standard deviation to the mean (average)
Coefficient of variation = (standard deviation/mean) × 100
×
=
5 · (6 - 1) + 3
= 5·5 + 3
= 25 + 3
= 28