Question

A car travels 130 km in $2\dfrac{1}{2}$hours.
*Find the time required to travel 240 km
*Find the distance travelled in 3 hours

Answer 1

Hint: In the above question we will try to find the speed of a car when it travels 130 km in $2\dfrac{1}{2}$hours. To find the time required by a car to travel 240 km we have to put the value of Speed of a car and the distance that is 240 in this formula ${\text{time = }}\dfrac{{{\text{distance}}}}{{{\text{speed}}}}$. Then to find the distance travelled by a car in 3 hours we will simply multiply speed with time taken.

Complete step-by-step answer:
Given,
Distance travelled by a car = 130 km
Time taken to cover this distance $ = 2\dfrac{1}{2} = \dfrac{5}{2}$hours
Speed of a car $ = \dfrac{{{\text{distance}}}}{{{\text{time}}}}$
$ = \dfrac{{130}}{{\dfrac{5}{2}}} = \dfrac{{130 \times 2}}{5} = 52$km/hour
Now, according to the question we have to find time required to travel 240 km.
We have, Speed of the car = 52 km/hour
Distance travelled by a car = 240 km
Time taken by a car to travel 240 km $ = \dfrac{{{\text{distance}}}}{{{\text{Speed}}}}$
$ = \dfrac{{240}}{{52}} = \dfrac{{60}}{{13}} = 4\dfrac{8}{{13}}$hours
Hence, the Time taken by a car to travel 240 km is $4\dfrac{8}{{13}}$ hours (Ans.)
Distance travelled in 3 hours by a car = Speed X Time
                                                                   = 52 X 3 = 156 km
Hence, the distance travelled in 3 hours by a car is 156 km.

Note: We have used a simple formula that is ${\text{speed = }}\dfrac{{{\text{distance}}}}{{{\text{time}}}}$in this question. This formula shows that Speed is directly proportional to distance but inversely proportional to time. Important point to note here is that if time is given in minutes, but speed is in kmph. Then, we have to either change the speed into km/min or time should be changed in hours.