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:
I think this is a pretty good question of law of indices
Step-by-step explanation:
Given that
a) express n in terms of p and q ,
b) hence if p = 1 and q = 2 find the value of n
Solution to part a)
Simplify the equation and how do we do that? As we can see that 9 can also be written as 3^2 and 27 can be written as 3^3 we can rewrite the following equation like this,
now we multiply p with 2 and
multiply q with 3 respectively,
now since the bases are same and are multiplying the exponents will add themselves like this, in this equation the number 3 is the base
now since the bases on the left hand side and on the right hand side are equal the exponents will also be equal so now,
hence n is expressed in terms of p and q
Solution to part b)
if p = 1 and q = 2 we plug in these values in the above equation we found for n
n = 2p + 3q
n = 2(1) + 3(2)
n = 2 + 6
n = 7
The equivalent number is 9013
Answer:
Timed test.
Step-by-step explanation:
An operational definition gives exactly what the independent variable means and its mode of measurement. The Independent variable is the variable in a research or experimental study which causes a change in the the measured variable. Hence, the independent variable is the predictor variable. In the study above, the independent variable is the timed test which is used to observe changes in the heart rate of the test taker (test anxiety). The change innheartrate of the test taker is the dependent variable.
