Step-by-step explanation:
Let the original speed of the train be x km/h.
Time taken to cover a distance of 360 km = 360/x hours.
New speed of the train = (x+5) km/h.
Time taken to cover a distance of 360 km at new speed = 360/x+5 hours.
Since, the train takes 1 hour less time,
∴360/x - 360/ x+5 = 1
⇒360 (5) = x² + 5x
⇒1800 = x² + 5x
⇒x² + 5x - 1800 = 0
⇒x² + 45x - 40x - 1800 = 0
⇒x (x+45) - 40( x +45) = 0
⇒(x+45) (x-40) = 0
⇒x = (-45), 40
But since speed cannot be in negative.
∴x = 40 km/hr.
Hence, the original speed of the train is 40 km/h.
Answer:
60
Step-by-step explanation:
area of triangle ACF is (1/2) (AC) (CF) = 180
area of triangle BCE = (1/2) (BC) (CE)
BC = AC/2
CE=(2/3) CF
so (1/2) (BC) (CE) = (1/2) (AC/2) (2/3)CF = (1/2)(2/3)(180) = 60 sq cm
Answer:
E
Step-by-step explanation:
The ordered pair numbers seemed to big so I guessed and I was right.
Answer:
<h2>
S = 250/t</h2>
Step-by-step explanation:
If the rate of change of sales is inversely proportional to the time t, this is expressed mathematically as ΔS ∝ 1/Δt
ΔS = k/Δt where k is the constant of proportionality
If ΔS = S₂-S₁ and Δt = t₂-t₁
S₂-S₁ = k/ t₂-t₁
If the sales after 2 and 4 weeks are 162 units and 287 units respectively, then when S₁ = 162, t₁ = 2 and when S₂ = 287, t₂ = 4.
On substituting this values into the given functions, we will have;
287 - 162 = k/4-2
125 = k/2
cross multiplying
k = 125* 2
k = 250
Substituting k = 250 into the function ΔS = k/Δt
ΔS = 250/Δt
S = 250/t
<em>Hence the value of S as function of t when the sales after 2 and 4 weeks are 162 units and 287 units, respectively is expressed as S = 250/t</em>
