Step-by-step explanation:
We want to find two things-- the speed of the boat in still water and the speed of the current. Each of these things will be represented by a different variable:
B = speed of the boat in still water
C = speed of the current
Since we have two variables, we will need to find a system of two equations to solve.
How do we find the two equations we need?
Rate problems are based on the relationship Distance = (Rate)(Time).
Fill in the chart with your data (chart attached)
The resulting speed of the boat (traveling upstream) is B-C miles per hour. On the other hand, if the boat is traveling downstream, the current will be pushing the boat faster, and the boat's speed will increase by C miles per hour. The resulting speed of the boat (traveling downstream) is B+C miles per hour. Put this info in the second column in the chart. Now plug it into a formula! <u>Distance=(Rate)(Time) </u>Now solve using the systems of equations!
Answer:
B he used the incorrect formula for the volume of the prism
If there is 10% of $18 = 18 x 0.9 (1 - 0.1) = $16.20
Therefore the pie costs $16.20
He is saving 18 - 16.20 = $1.80
D would be the answer ^^ Hope this helps!! :) Good luck
1584 lightbulbs would be defective out of 4400