The first one. It is called an exponential decay curve.
Answer:
cent/km
Step-by-step explanation:
Given


Required
The fuel cost in 
This is calculated using:




Multiply by
to get the cost in cents
cent/km
cent/km
It’s 80 for sure Ik this one
to be sure that 2 of them will be blue i have to select 7+2=9 balls
7+8=15 balls in the urn
P=9/15
to be sure that 4 of them will be yellow i have to select 8+4=12 balls
P=12/15