51 inches is 2 inches more than the mean, which is 1 standard deviation.
Using the 68, 95, 99.7 rule:
100-68 / 2 = 16% would be taller than 51 inches.
So we know that Kevin has 17 cards. The total number of cards that Billy has is 17 plus an unespecified number t. THis means that we have an addition of cards then the total number of cards that Billy has is given by:

And the correct option is A.
Answer:
1, 3, 5 or 1, 2, 3 I think? Sorry if its not
Answer:
3 Blue Umbrellas
Step-by-step explanation:
Given



From the question, we have:
---- i.e. 6 are not blue
---- i.e. 6 are not yellow
---- i.e. 6 are not red
Required
The number of blue umbrellas
Make B the subject in: 

Substitute:
in 

Collect like terms


Rewrite:

Substitute
in 


Divide both sides by 2

Recall that: 


Answer:
# 2,9 are declareitive .......... .......