Question

13, Amar ran a mar,
14. Bina has to travel a distance of 1620 km. She travels 1200 km by an aeroplane at 800 km/h,
300 km by car at a speed of 60 km/h and the remaining distale at 48 km/h by bus. Calculate
a, the time taken by plane, car and bushyhe average speed of the journey
at 80 km/h​

Answer 1

Answer:

180 km/hr

Step-by-step explanation:

    1200 km by aeroplane:

⇒ speed = distance/time

⇒ time = distance/speed

           = 1200/800 =  1.5 hr

Similarly, 'when by car':

⇒ time = 300/60 = 5 hr

   Remaining dist. = 1620 - 1200 - 300

                               = 120 km

              When by bus:

⇒ time = 120/48 = 2.5 hr

       Total distance = 1620

 Total time = 1.5 + 5 + 2.5 = 9hr

Hence,

Average speed = 1620/9 = 180 km/hr

Answer 2

$\mathcal{\gray{\underbrace{\blue{GIVEN:-}}}}$

• Bina has to travel a distance of 1620km .

• She travels 1200km by an aeroplane at 800km/h .

• 300km by car at 60km/h .

• Remaining distance covered by bus at 48km/h .

$\mathcal{\gray{\underbrace{\blue{TO\: FIND:-}}}}$

• Time taken by Plane .

• Time taken by Car .

• Time taken by Bus .

• Average speed of the journey .

$\mathcal{\gray{\underbrace{\blue{CALCULATION:-}}}}$

$\pink\bigstar\:\rm{\red{\boxed{\purple{Time\:=\:\dfrac{distance}{speed}\:}}}}$

⚡ Time taken by Plane :-

=> Time = 1200/800 = 3/2 h = 1.5 h .

⚡ Time taken by Car :-

=> Time = 300/60 = 5 h .

✍️ Remaining distance,

= 1620 - (1200 + 300)

=> Remaining distance = 1620 - 1500

=> Remaining distance = 120km .

⚡ Time taken by Bus :-

=> Time = 120/48 = 2.5 h .

Hence, total time taken = (1.5 + 5 + 2.5) h

=> Total time = 9h .

$\pink\checkmark\:\mathcal{\red{\boxed{\purple{Average\:Speed\:=\:\dfrac{Total\:distace}{Total\:time}\:}}}}$

=> Average speed = 1620/9 = 180km/h .

$\rm\green{\therefore}$$<font color=pink>$ The average speed of the journey is 180km/h .