The graphs shown below represent the average temperature in four U.S.
cities at different months throughout the year. Which graph represents
the greatest rate of change from March to April?

need help ASAP .

Rate of Bill's boat = 14 miles per hour

Speed of the current = 2 miles per hour

Step-by-step explanation:

Let x = the rate of the boat in still water and y = the rate of the current.

Distance traveled = 24 miles

Time taken for upstream motion = 2 hour

Time taken for downstream motion = 1.5 hour

Velocity of upstream motion = x - y

Velocity of downstream motion = x + y

We have

           Displacement = Time x Velocity

Upstream motion

            24 = 2(x-y)

             x - y = 12 eqn 1

Downstream motion

            24 = 1.5(x+y)

             x + y = 16 eqn 2

eqn 1 + eqn 2

             2 x = 28

                x = 14 miles per hour

Substituting in eqn 2

                 14 + y = 16

                      y = 2 miles per hour

Rate of Bill's boat = 14 miles per hour

Speed of the current = 2 miles per hour