Answer:
15 years
Step-by-step explanation:
Since we're looking for time, we can use the formula t = A / Pr, which would be:
t = 6000/(7255 x 5.5%)
Converting the percentage into decimal form
t = 6000/(7255 x 0.055)
We can then solve to get:
t = 6000/399.025
t = 15.03665183...
Meaning it would take 15 years for an interest of 5.5% on $6,000 to reach $7,255. Not very worth $1,255 extra if you need that 6k for rent.
Answer:
i)W = 2500 / T
ii) W = 500 Tons
iii) grad W(10°) = - 25î
iv) The formulation is not practical
Step-by-step explanation:
i) Write an equation describing the use of coal
As use of coal is inversely proportional to the average monthly temperature
if W is use of coal in tons/per month then
W(t) = k / T where k is a constant of proportionality and T is the average temperature in degrees. We have to determine k from given conditions
k = ?? we know that when T = 25° W = 100 tons the by subtitution
W = k/T 100 = k /25 k = 2500 Tons*degree
Then final equation is:
W = 2500 / T
ii) Find the amount of coal when T = 5 degrees
W = 2500 / 5
W = 500 Tons
iii)
The inverse proportionality implies that W will decrease as T increase.
The vector gradient of W function is:
grad W = DW(t)/dt î
grad W = - 2500/T² î
Wich agrees with the fact that W is decreasing.
And when T = 100°
grad W(10°) = - 2500/ 100 î ⇒ grad W(10°) = - 25î
iv) When T = 0 The quantity of coal tends to infinite and the previous formulation is not practical
1/49=x^2 where x is the side of the square
1/49=(1/7)^2, so the side length of the square is 1/7
