Answer:
Hope this helps.
Step-by-step explanation:
Answer:
2 km/h
Step-by-step explanation:
Let x represent the speed of the river current, t₁ be the time spent rowing against the current and t₂ be the time spent rowing with the current.
Since the speed of the still water = 20 km/h.
The speed of rowing against the current = (20 - x)
The speed of rowing with the current = (20 + x)
We know that velocity = distance / time. Hence time = distance / velocity
t₁ = 36 / (20 - x)
t₂ = 22 / (20 + x)
but t₁ + t₂ = 3 hours
Therefore:
3 = 36 / (20 - x) + 22 / (20 + x)
multiply through by 400 - x²
3(400 - x²) = 36(20 + x) + 22(20 - x)
1200 - 3x² = 720 + 36x + 440 - 22x
3x² + 14x -40 = 0
This gives x = -6.7 or x = 2
x cannot be negative therefore x = 2 km/h
The speed of the river current is 2 km/h
Answer:
If 32 students are enrolled in the course, there would be 24 girls.
Step-by-step explanation:
Given that For every boy in an advanced math course there are 3 girls who are taking the course.
It means if there are four students in the class. There would be 3 girls and 1 boy. Thus, 75% of the students are girls.
Given that there are 32 students enrolled in the course.
so
75% of 32 = 75/100 × 32
= 24
Thus, if 32 students are enrolled in the course, there would be 24 girls.
Answer:
400
Step-by-step explanation:
He makes $4 per shirt ($12-$8). $1600/4 = 400. So he woud need to see at least 400 shirts to break even.
