Answer:
9 hours, 20 minutes
Step-by-step explanation:
When two ferries work together, they transport a day's cargo in 7 hours
The speed proportion or ratio of larger ferry to smaller ferry is given as 3 : 1
The sum of the ratio = 4 (3 + 1)
This means that it will take the smaller ferry = 7 x 4 hours to work alone = 28 hours, since the larger ferry is faster by 3.
Therefore, when larger ferry works alone, it will take it (7 x 4)/3 = 9.33 hours.
9.33 hours = 9 hours, 20 minutes.
Answer:
Step-by-step explanation:
Just did a specific one of these; let's do the general case.
The point nearest the origin is (a,b).
The line from the origin through the point is

The line we seek is perpendicular to this one. We swap the coefficients on x and y, negating one, to get the perpendicular family of lines. We set the constant by plugging in the point (a,b):


That's standard form; let's plug in the numbers:


An equilateral triangle has 3 equal sides and angles. Each angle is
60 degrees.
Answer:


Step-by-step explanation:
Given




Required
The number of each coin
The total coins can be represented as:


So, the worth of the coin is:

The equations to solve are:


Make d the subject in: 

Substitute
in 


Collect like terms


Solve for q


Substitute
in 


So:

