3,000 yd3 = 200 dtl
Chapter 1: Problem Solving 17 / 21
Rates Question
12 A highway had a landslide, where 3,000 cubic yards of material fell on the road, requiring 200 dump truck loads to clear. On another highway, a slide left 40,000 cubic yards on the road. How many dump truck loads would be needed to clear this slide?
3,000 yd3 = 200 dtl
40,000 yd3 × 200 dtl = 2,667 dtl
3, 000 yd3
Answer:
<h2>14mph</h2>
Step-by-step explanation:
Given the gas mileage for a certain vehicle modeled by the equation m=−0.05x²+3.5x−49 where x is the speed of the vehicle in mph. In order to determine the speed(s) at which the car gets 9 mpg, we will substitute the value of m = 9 into the modeled equation and calculate x as shown;
m = −0.05x²+3.5x−49
when m= 9
9 = −0.05x²+3.5x−49
−0.05x²+3.5x−49 = 9
0.05x²-3.5x+49 = -9
Multiplying through by 100
5x²+350x−4900 = 900
Dividing through by 5;
x²+70x−980 = 180
x²+70x−980 - 180 = 0
x²+70x−1160 = 0
Using the general formula to get x;
a = 1, b = 70, c = -1160
x = -70±√70²-4(1)(-1160)/2
x = -70±√4900+4640)/2
x = -70±(√4900+4640)/2
x = -70±√9540/2
x = -70±97.7/2
x = -70+97.7/2
x = 27.7/2
x = 13.85mph
x ≈ 14 mph
Hence, the speed(s) at which the car gets 9 mpg to the nearest mph is 14mph
Answer:
Ryan takes 6n+36m -42 seconds to reach the nth flag for the mth time.
Step-by-step explanation:
It takes Ryan to run from 1st to 6th flag in 30 seconds, so it takes him
30 * 6/3 = 36 seconds to make one complete round.
or it takes 6 seconds to run from one flat to the next.
To reach the nth flag (n=1,2,3,4,5, or 6)
Ryan takes 6(n-1) seconds.
To reach it the mth times, he needs to add 36(m-1) seconds.
So time it takes Ryan to reach the nth flag for the mth time takes
6(n-1) + 36(m-1)
= 6n - 6 + 36m - 36
= 6n+36m -42 seconds
Joan's remaining distance is reduced by (600 ft)/(3 hours) = 200 ft/hour. She starts with 1600 ft remaining, so her distance remaining (y) after x hours is
.. y = -200x +1600
In order for the distance remaining to be zero, you must have
.. 0 = -200x +1600
.. 200x = 1600
.. x = 1600/200 = 8
It will take Joan 8 hours to hike 1600 ft.
