Answer:
Option E.
Step-by-step explanation:
Let the intended length of Rebecca's swimming is = x units
and we assume the length of the pool = l units
Now it is given in the question that " She covers one fifth of her intended distance "
That means distance covered = 
" After swimming six more lengths of the pool she had covered one quarter of her intended distance"
So 


x = 20×(6l)
x = 120l
Therefore, Rebecca has to complete 120 lengths of the pool.
Option E is the answer.
Answer:
It is given that a car traveling at 23 mi/h accelerates to 46 mi/h in 5 seconds.
This means that in 5 seconds it's speed continuously increases to reach 46 mi/h from 23 mi/h.
It maintains that speed for 5 seconds and then slows to a stop in 5 seconds.
This means that the speed of the car is constant i.e. 46 mi/h i.e. the graph is a straight horizontal line parallel to the time axis.
And then it decreases to reach 0 mi/h.