This is the way I do it to find the average.
10 girls times 70 = 700
15 boys times 80= 1200
700+1200=1900 all their scores
1900÷25 (number of boys and girls)=76 or 76%
Answer:
1) yes 2) no 3) yes
Step-by-step explanation:
The lengths of the two shorter sides must be greater than the length of the longest side.
1) 8 + 9 > 10 yes
2) 1 + 1 = 2 no
3) 6 + 8 > 9 yes
Answer:
Wyzant
Question
Flying against the wind, an airplane travels 4200 km in 7 hours. Flying with the wind, the same plane travels 4000 km in 4 hours. What is the rate of the plane in still air and what is the rate of the wind?
Answer · 1 vote
Let Va = the velocity of the airplane Let Vw = the velocity of the wind When flying with the wind: (Va+Vw)*(4 hours) = 4000 4Va + 4Vw = 4000 4Vw = 4000 - 4Va Vw = 1000 - Va When flying against the wind: (Va-Vw)*(7 hours) = 4200 km7Va - 7Vw = 4200 Substitute 1000-Va for Vw and solve for Va: 7Va - 7(1000-Va) = 4200 7Va -7000 + 7Va = 4200 14Va = 11200 Va = 800 km/hr Rate of wind: Vw = 1000 - Va = 1000 - 800 = 200 km/hour
More
Socratic
Question
Flying against the wind, an airplane travels 4500 in 5 hours. Flying with the wind, the same plane travels 4640 in 4 hours. What is the rate of the plane in still air and what is the rate of the wind?
Answer · 0 votes
The speed of plane in still air is 1030 km/hr and wind
Step-by-step explanation:
Answer:
It's y=4x+3
Step-by-step explanation:
if you find the slope m=(y2-y1)/(x2-x1). Then you know the y-intercept is 3 because it gives you the point (0,3).
Answer:
40
Step-by-step explanation:
Two ways we can solve this problem:
1. Graphically
2. Mathematically
Because you already solved it graphically, I will show you how to do so mathematically. Of course, graphically is much much easier and more efficient in this problem.
Let's break the problem down.
First, we are given a graph which contains a slope.
To find slope, we use the technique -> rise/run
Picking 2 obvious points from the graph, we can see
1st point -> (10, 20)
2nd point -> (40, 80)
Now, let's find the slope
Now, we have an equation y = 2x, where y = number of pies and x = cups of sugar
We want to find how many cups of sugar we need to bake 80 pies. Simply substitute 80 = number of pies = y
y = 2x -> 80 = 2x
Solving for x, divide both sides by 2
40 = x
We need 40 cups of sugar.
