Ontem = 1/2 h = 0,5 h = 30 min
hoje = 4 h + 1/3 h = 1 h + 60/3 = 1 h e 20 min = 80 min
30 min + 80 min = 110 min
110 min.................54
60 min....................x
11x = 54*6
11x = 324
x = 324/11
x ~ 29,45 por hora
Answer:
They can make 10 different groups of three.
Step-by-step explanation:
The order in which the people are in the car is not important, so we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
How many different groups of three can the five of them make?
Combinations of 3 from a set of 5. So
They can make 10 different groups of three.
Answer:
2000 meters
Step-by-step explanation:
When the motorboat is moving downstream, its speed relative to the ground is 18 km/h, so its speed relative to the raft is 15 km/h.
When the motorboat is moving upstream, its speed relative to the ground is 12 km/h, so its speed relative to the raft is again 15 km/h.
Converted to m/min, the relative speed is:
15 km/h × (1000 m/km) × (1 h / 60 min) = 250 m/min
It takes the motorboat 16 minutes to travel to the front of the raft and back. Since the speed is the same in both directions, the motorboat takes 8 minutes to travel the length of the raft.
So the length of the raft is 250×8 = 2000 meters.
