Question

EXERCISE 17(A)
A train covers 51 km in 3 hours. Calculate its speed. How far does the train go in
30 minutes ?​

Answer 1

Answer:

speed = 17km/hr

in 30mins it will cover 8.5km

Step-by-step explanation:

distance(d) = 51km

time(t) = 3 hrs

speed = d/t

therefore, speed = 51/3 km/hr

                            = 17km/hr

30 mins is 1/2 hrs

17 * 1/2 km

= 8.5 km

Answer 2

To Find :-

• The speed of the Train.

• The distance covered in 30 min

Given :-

• Distance = 51 km

• Time Taken $t_{1}$ = 3 hours.

• Time taken $t_{2}$ = 30 min or ½ hours .

We Know :-

Speed :-

$\underline{\boxed{\bf{Speed = \dfrac{distance}{Time}}}}$

Concept :-

According to the question , The same train is taken here , so the speed of the train will be Equal in both the different time and thr distance will also be different.

Solution:-

To Find the Speed of the Train :–

Given :-

• Distance = 51 km

• Time taken = 3 hours.

Using the formula and substituting the values in it , we get :-

$:\implies \bf{Speed = \dfrac{Distance}{time}} \\ \\ \\ :\implies \bf{Speed = \dfrac{51}{3}} \\ \\ \\ :\implies \bf{Speed = 17 km h^{-1}} \\ \\ \\ \therefore \purple{\bf{Speed = 17 km h^{-1}}}$

Hence, the speed of the train is 17 km/hr.

To Find the Distance covered in 30 min :–

Given :-

• Time = ½ hrs.

• Speed = 17 km/hr.

Using the formula and substituting the values in it , we get :-

$:\implies \bf{Speed = \dfrac{Distance}{time}} \\ \\ \\ :\implies \bf{17 = \dfrac{Distance}{\dfrac{1}{2}}} \\ \\ \\ :\implies \bf{17 = 2 \times Distance} \\ \\ \\ :\implies \bf{17 \times \dfrac{1}{2} = Distance} \\ \\ \\ :\implies \bf{8.5 km = Distance} \\ \\ \\ \therefore \purple{\bf{Distance = 8.5 km}}$

Hence, the Distance covered in ½ hour or 30 min is 8.5 km.