Answer:
B
Step-by-step explanation:
Answer:
- train: 40 kph
- plane: 140 kph
Step-by-step explanation:
Let t represent the speed of the train in km/h. Then 4t-20 is the speed of the plane. Travel times are the same, so we can use the formula ...
time = distance/speed
and equate the travel times.
110/t = 385/(4t-20)
Cross multiplying gives ...
110(4t -20) = 385t
440t -2200 = 385t . . . . . eliminate parentheses
55t -2200 = 0 . . . . . . . . . subtract 385t
t -40 = 0 . . . . . . . . . divide by 55
t = 40 . . . . . . . . . . . add 40; train's speed is 40 kph
4t -20 = 140 . . . . . . find plane's speed; 140 kph
The train's speed is 40 km/h; the plane's speed is 140 km/h.
_____
<em>Check</em>
Train's travel time = 110 km/(40 km/h) = 2.75 h.
Plane's travel time = 385 km/(140 km/h) = 2.75 h.
Answer: 2t + 18
Step-by-step explanation:
Answer:
108points
Step-by-step explanation:
Let Caleb score be x and that of Mike be y. If Caleb and Mike both score the same amount of points in a game, then x = y.
The total number of option = x+y
Now, If Caleb has fifteen less than the total number of options, then;
x =(x+y)-15
x -(x+y)+15 = 0
x-x-y = -15
-y = -15
y = 15
Also if Mike has twice the total number of points decreased 201, then;
y = 2(x+y)-201
Since y = 15
15 = 2(x+15)-201
15 = 2x+30-201
15 = 2x-171
2x = 15+171
2x = 186
x = 186/2
x = 93
The total number of points they have altogether is x+y
x+y = 15+93
x+y = 108
Hence the total points that they have altogether is 108points
