36/20
36:20
36 to 20
hope this helps
I believe $1, two of the friends left, if it's not the correct answer I'm sorry.
The average speed is given by:
average speed=(total distance)/(total time)
total time for the first 30 miles was:
time=distance/speed
=30/30
=1 hr
total time for the remaining 30 miles
=30/60
=0.5
hence the average speed will be:
speed=(30+30)/(1+0.5)=60/1.5=40 miles per hour
Could you attach an image of the slope? Because i dunno what lesson you're on....
:/
If we just have

that's an amplitude of 1 and a period of 
Let's modify this step by step.
Amplitude of 4. Four times the amplitude means a factor of 4 on the outside.

Period of π. Double the period means a factor of 2 on the inside.

Horizontal shift of π/2 to the left. To the left means adding a positive number to x. The question appear ambiguous. It's not clear to me if we add to x or 2x; let's make it

Vertical shift of 3:


Depending on the interpretation of the phase shift, that pi may be a pi/2.
Answer: 