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.
Answer:
40
Step-by-step explanation:
So, difference as in subtract? so, if it is, it would be 15. if it means percent difference, it's about 60%.
Make an equation system based on the problem
eg. a is the first number and b is the seond number
An equation for "<span>The sum of two numbers is 53" is
</span>⇒ a + b = 53
An equation for "<span>twice the first number minus three times the second number is 26"
</span>⇒ 2a - 3b = 26
<span>
Solve the equations by elimination and subtitution method
Eliminate a to find the value of b
a + b = 53 (multiplied by 2)
2a - 3b = 26
--------------------------------------
2a + 2b = 106
2a - 3b = 26
------------------- - (substract)
5b = 80
b = 80/5
b = 16
Subtitute the value of b to one of the equations
a + b = 53
a + 16 = 53
a = 53 - 16
a = 37
The numbers are 16 and 37</span>
