Mathematics
A train covers a distance of 780 km at x km/hr. Had the speed been (x − 5) km/hr, the time taken to cover the same distance would have been increased by 1 hour. Write down an equation in x and solve it to evaluate x.
Related Questions
By increasing the speed of a car by 10 km/hr, the time of journey of 72 km is reduced by 36 minutes. Find the original speed of the car.
A train covers a distance of 600 km at x km/hr. Had the speed been (x + 20) km/hr, the time taken to cover the same distance would have been reduced by 5 hours. Write down an equation in x and solve it to evaluate x.
The distance by road between two towns A and B, is 216 km, and by rail it is 208 km. A car travels at a speed of x km/hr and the train travels at a speed which is 16 km/hr faster than the car.
(i) Write down the time taken by the car to reach town B from A, in terms of x.
(ii) Write down the time taken by the train to reach town B from A, in terms of x.
(iii) If the train takes 2 hours less than the car to reach town B, obtain an equation in x and solve it.
(iv) Hence, find the speed of the train.
Car A travels x km for every litre of petrol, while car B travels (x + 5) km for every litre of petrol.
(i) Write down the number of litres used by car A and car B in covering a distance of 400 km.
(ii) If car A used 4 litres of petrol more than car B in covering 400 km, write an equation in x and solve it to determine the number of litres of petrol used by car B for the journey.