Answer:
Distance between the two check point (C and D) is 4920 ft.
Step-by-step explanation:
From the question given above, we obtained the following information:
X is 6000 ft from C (1st check point)
D (2nd check point) is the midpoint point between C and Y ( the end of the race)
Total race = 3 miles
1 mile = 5280 ft
Next, we shall express the total race in feet (ft).
This is illustrated below:
1 mile = 5280 ft
Therefore,
3 miles = 3 × 5280 = 15840 ft
Next, we shall determine the distance between the 1st check point (C) and the end of the race (Y)
This can be obtained as follow:
Total distance = 15840 ft
Distance between X and C = 6000 ft
Distance between C and Y =?
Distance between C and Y = (Total distance) – (Distance between X and C)
Distance between C and Y = 15840 – 6000
Distance between C and Y = 9840 ft
Finally, we shall determine the distance between the two check point (C and D) as follow:
Since D is midpoint between C and Y, therefore, we shall we shall divide the distance between C and Y by 2 in order to obtain the distance between the two check point (C and D).
This is illustrated below:
Distance between C and Y = 9840 ft
Distance between the two check point (C and D) = 9840/2 = 4920 ft
Therefore, the distance between the two check point (C and D) is 4920 ft
for an example. If the number is increased by 60% and the denominator is decreased by 20% we get the new fraction being: 
. Since then new one is equal to 1, and the original is equal to 
, we see that this manipulation of the fraction causes an increase of 100%.