Help me with Maths. It’s for a good cause. ?????

Average Speed = Total Distance / Total time

Speed AB = D/3Speed BC = D/5Speed AC = 2D/8 = D/4Ans:Speed AB:AC = (D/3) : (D/4) = 4:3

Let v₁ km/h be the average speed for distance AB, and vₒ km/h be the average speed for the whole distance AC.

Distance AC = (Distance AB) + (Distance BC)
Then, Distance AC = (Distance AB) × 2
(vₒ km/h) × [(3 + 5) h] = (v₁ km/h) × (3 h) × 2
8vₒ = 6v₁
v₁/vₒ = 8 : 6

Average speed for distance AB : average speed for the whole distance AC = 4 : 3

d = rt, ie., distance = rateXtime.;
A to B. d/r1 =... 3h, r1 =...d/3h;
B to C. d/r2 =... 5h, r2 =...d/5h;
A to C. 2d/r3 =..8h, r3 = 2d/8h = d/4h;
r1:r3 = (d/3h):(d/4h) = 1:((d/4h)/(d/3h)) = (3/4). so r1:r3 = 4:3.   

Recall: s = d/t → where s is the speed, d is the distance, t is the time


The car travels from A to B in 3 hours.

s = d/t ← adapt this formula to the current case

s₁ = d₁/3


The car travels from B to C in 5 hours.

s = d/t ← adapt this formula to the current case

s₂ = d₂/5


Average speed from A to C

s = d/t ← adapt this formula to the current case

s₃ = (d₁ + d₂)/(t₁ + t₂)

s₃ = (d₁ + d₂)/(3 + 5)

s₃ = (d₁ + d₂)/8 → given that: AB = BC → d₂ = d₁

s₃ = 2.d₁/8

s₃ = d₁/4 → recall: s₁ = d₁/3 → d₁ = 3.s₁

s₃ = (3.s₁)/4

s₁/s₃ = 4/3