Question

Jignesh Travels x km at 60 km per hour and other 3x at 90 km per hour what is the average speed over distance​

Answer 1

Answer:

Average speed is 80 kmph

Step-by-step explanation:

T = t1+t2

D/S = d1/s1 + d2/s2

(d1+d2)/S = d1/s1 + d2/s2

(x+3x)/S = x/60+3x/90

4x/S = x/60+x/30

4x/S = x/60+2x/60

4x/S = 3x/60

4/S = 3/60

4/S = 1/20

80 = S

Answer 2

Answer:

The average speed for is 80km/hr

Step-by-step explanation:

We know:

Speed = $\frac{Distance}{Time}$

Given:

For first distance,

Distance  = x km

Speed  = 60km/hr

Therefore, time taken = x/60 hrs

For second distance,

Distance  = 3x km

Speed  = 90km/hr

Therefore, time taken = 3x/90 hrs = x/30 hrs

We know that average speed = $\frac{Total Distance}{Total Time}$

Total distance = x + 3x = 4x

Total time  = $\frac{x}{60}$ + $\frac{x}{30}$ = $\frac{x + 2x}{60}$ = $\frac{3x}{60}$ = $\frac{x}{20}$

Therefore, average speed = $\frac{4x}{\frac{x}{20}}$

                                            = $\frac{4x*20}{x}$

                                            = 80

Therefore, the average speed for is 80km/hr