Answer:
30 mph
Step-by-step explanation:
Let d = distance (in miles)
Let t = time (in hours)
Let v = average speed driving <u>to</u> the airport (in mph)
⇒ v + 15 = average speed driving <u>from</u> the airport (in mph)
Using: distance = speed x time

Create two equations for the journey to and from the airport, given that the distance one way is 18 miles:

We are told that the total driving time is 1 hour, so the sum of these expressions equals 1 hour:

Now all we have to do is solve the equation for v:







As v is positive, v = 30 only
So the average speed driving to the airport was 30 mph
(and the average speed driving from the airport was 45 mph)
B 5 makes the most sense to me
Answer:
d=8√2 = 11.31
x=3√3 = 5.20
y=6√3 = 10.39
Step-by-step explanation:
d²=8²+8²
d²=64+64
d²=128
d=√128
d=√64*2
d=8√2 = 11.31
30-60-90 triangle
x-x√3-2x
x√3=9
x=9/√3
x=3√3
y=2x
y=2 * 3√3
y=6√3
No this is not a valid reference because those were 20 random families, if he does another test the next twenty families 50% of them could attend the party. Too much chance to be valid.