Answer:
0.5 hour
Step-by-step explanation:
Given
Speed of Dina = 10 km/h
Distance = 20 km
So the time Dina taken to complete the track is:

The time taken by Dina is 2 hours. As masha started with dina but she was 4 km of the path left to cycle,
her distance covered in 2 hours was:

So we know the time and distance:
Now,

We have to calculate the time that will be needed by MAsha to complete the track:
As we know the speed and remaining distance

Masha needs 0.5 hour to complete the track ..
42 feet to 6 feet can be written as both ratio and a fraction:
42:6
42/6
If we look at the fraction, we can clearly see that we can simplify it:
42/6 = 7/1 = 7
So we can write the ratio in its lowest terms as 7:1.
Solve the inequality for x:
5x - 3 ≤ 7x +7
Subtract 7x from each side:
-2x -3 ≤ 7
Add 3 to each side:
-2x ≤ 10
Divide both sides by -2, also when dividing both sides of an inequality you flip the direction of the inequality sign:
x ≥ -5
The dot will be on -5, because the inequality includes equal to, the dot is solid and is greater than, the arrow will point to the right.
The correct answer is D.
Ranking is very critical in this problem. Therefore, the most applicable mathematical theory is permutations.
Ranking possible for the cellists:
Needed cellists = 5
Total available cellists = 10
Possible number of rankings = 10P5 = 10!/(10-5)! = 30240
Ranking possible for the violinists:
Needed violinists = 5
Total available = 16
Possible number of rankings = 16P5 = 16!/(16-5)! = 524160
Therefore,
Ratio of rankings (cellists to violinists) = 30240/524160 = 3/52