The probability of the union of two events is the sum of their probability, minus the probability of their interserction:
If we plug the known values into this formula, we have
From which we can deduce
So, the probability of 
is a bit less than 
, we have to take away all events that belong to B as well:
Multiply each number by 3.
2 (x 3) is 6. 6 x 3 is 18, 18 x 3 is 54, 54 x 3 is 162.
Hope this helps!
Ok, let's find how much does 1 yard of ribbon cost. Let's divide!
Each yard costs $1.50, so let's multiply that by 10
Marci will pay $15 for 10 yards of the ribbon.
A=adult tickets
c=chlderenticekts
s=sinior tickets
a=c
a+c+s=120
2a+s=120
total made is 1100
12a+6c+10s=1100
sub
a=c
12a+6a+10s=1100
add
18a+10s=1100
multiply first equation by -9 and add to other equation
-18a-9s=-1080
18a+10s=1100 +
0a+s=20
s=20
20 senior tickets were sold
answer is B
If you are looking for volume you want v by itself so your formula would look like this : d*m=v
hope this helps
