The answer is 12
12-(5+3)=4
4+8=12
3x + 9 = 90
3x = 90 - 9 = 81
x = 81/3 = 27
x = 27
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 ..
The volume of a cylinder is Pi times the radius^2 times the height
Volume = Pi x 6^2 x 2
Volume = 226.2