Answer:
162 [m²].
Step-by-step explanation:
required surface is:
A=(3*7+6*7+3*6)*2=162 [m²].
Answer:
Robyn model makes more sense and Marks is nonsense.
Step-by-step explanation:
In this question ,calculations not required .All we have to do is consider each model logically .
Marks
Marks model shows 20 rather than 2 which means 200 is 10 times as much as 20. It does not make any sense.
Robyn
Robyn model shows 2 which means 200 is 100 times as much as 2 and this is not only correct but also makes sense because 100 *2=200
Answer:
Step-by-step explanation:
To find the perimeter, you would have to add all the expressions together, so you would get 2x+x+x+y+y+1+y+y
combine like terms and you will get 4x+4y+1
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.
