Question

Asin can walk at a speed of 5 km/hr. How much will she cover in 2 hours?

Answer 1

ANSWER

Step-by-step explanation:

Formula: Speed = Distance/ Time, Therefore, Time = Distance / speed

Given that speed of the car is 20km/hr more than the average speed of the bus, Let the speed of the bus be x, 

Therefore speed of the car is x+20.

Average speed of the bus:

300/x - 4=300/x+20

=> 300[x+20-x/x(x+20)]= 4

=> 300(20/ x(x+20)) = 4

=> 300(20/x²+20x) = 4 (upon cross multiplying)

=> 6000= 4x²+80x

4x²+80x-6000=0

4(x²  + 20x -1500) =0

x²+20x-1500=0

Upon factorizing, 

(x+50)(x-30)=0

x=30

The bus goes 30 kmph; the car goes 50 kmph