Question

a car moves with the speed of 40km/h 15 minutes and then with the speed of 60km/h for 15 minutes the the total distance covered by the car is __________​

Answer 1

Given data:

Speed, S1​ is 40 km/hr

Speed, S2​ is 60 km/hr

Time, T1​ is 15 minutes =41​ hr

Time, T2​ is 15 minutes =41​ hr

Using S1​ and T1​ in the equation:

Distance = Speed ×Time

D1​=S1​×T1​

  =40×41​

  =10 kms

Using S2​ and T2​ in the equation:

Distance = Speed × Time

D2​=S2​×T2​

   =60×41​

   =15 kms

Total kms covered =D1+D2=10+15=25 km

Answer 2

$\large {\green {\sf {\underline {\underline {Step-by-step \: Explanation}}}:-}}$

(i) In the first case:

Speed = 40 km/h

Time taken = 15 minutes

Since, 1 hour = 60 minutes

$Therefore, \: time \: taken = \frac{15}{60} \: h = \frac{1}{4} \: h \\ \\ We \: know \: that, \: Speed = \frac{Distance \: travelled}{Time \: Taken } \\ \\ or, \: Distance \: travelled = Speed × Time Taken \\ \\ = 40 \: km/h \times \frac{1}{4} h \\ \\ ∵ \: Distance \: travelled = 10 \: km$

(ii) In the second case:

Speed = 60 km/h

Time taken = 15 minutes

$→ \: \frac{15}{60}h = \frac{1}{4}h \\ \\ We \: know \: that, \: Speed = \frac{Distance \: travelled }{Time \: taken} \\ \\ ∵ \: Distance \: travelled = Speed × Time \: taken \\ \\ = 60 km/h \times \frac{1}{4} \: h = 15 \: km \\ \\ Total \: distance \: travelled = 10 \: km + 15 \: km = 25 \: km$

This, the total distance covered by the car is 25 km.

$\large\color{blue}{I \: hope \: it \: helps \: you.}$

$\huge\dag\sf\red{By \: Divyanshu}$