Question

A car moves with a speed of $40$km$/$h for $15$ minutes and then with a speed of $60$ km$/$h for the next $15$ minutes. The total distance covered by the car is :

• A. $100$km
• B. $25$km
• C. $15$km
• D. $10$km

Answer 1

The correct option is B $25$km

Given data:

Speed, $S_1$ is 40 km/hr

Speed, $S_2$ is 60 km/hr

Time, $T_1$ is 15 minutes $=\frac{1}{4}$ hr

Time, $T_2$ is 15 minutes $=\frac{1}{4}$ hr

Using $S_1$ and $T_1$ in the equation:

Distance $=$ Speed $\times$Time

$D_1=S_1\times T_1$

$=40\times \frac{1}{4}$

$=10$ kms

Using $S_2$ and $T_2$ in the equation:

Distance $=$ Speed $\times$ Time

$D_2=S_2\times T_2$

$=60\times \frac{1}{4}$

$=15$ kms

Total kms covered $=D1+D2=10+15=25$ kms.