Answer:
2 km/h
Step-by-step explanation:
- distance = speed × time
- time = distance/speed
Let c represent the speed of the current of the river in km/h. Then the speed of the boat upstream is (10-c). In 3/4 hour, the distance traveled upstream is ...
... distance upstream = (3/4)·(10 -c)
The time taken to travel the same distance downstream is given as 3 hours. The speed in that direction is c, so we have ...
... 3 = distance upstream/c = (3/4)(10 -c)/c
Multiplying this equation by 4c, we get ...
... 12c = 3(10 -c)
... 15c = 30 . . . . . . . . add 3c
... c = 2 . . . . . . . . . . . divide by 15
The speed of the river current is 2 km/h.
Answer:
y = 120
Step-by-step explanation:
If y = 32 when x = 8, then <em>y</em> is 4 times the number of <em>x</em>. If x = 30, then (4)30 = 120.
Answer:
399
Step-by-step explanation:
it none of those I can tell you that
The first one is the correct answer