Question

7. Train P travels for 330 km at an average speed of x km h^-1 from Kuala Lumpur to Kota Bahru. Train Q travels from Kota Bahru at an average speed of (x- 5). km h^-1 and arrives at Kuala Lumpur 30 minutes earlier than train P. Calculate the total time, in hours, taken by the two trains.​

Answer 1

Answer:

Your AN$W€®

Time taken by train P: 330/x. Time taken by train

Q: 330/(x-5). (330/x) - (1/2) = 330/(x-5). (660 - x)(x - 5) = 330(2x) => x² - 5x + 3300 = 0 which has no real solution. On the other hand: (330/x) + (1/2) = 330/(x-5). (660 + x)(x - 5) = 330(2x) => x² - 5x - 3300 = 0 leads to (x - 60)(x + 55) = 0 which gives x = 60.

• Time taken by train P = 330/60 = 5.5 h. Time taken by train Q = 330/55 = 6 h which is 30 min later.

____________________________

Answer 2

Time taken by train P: 330/x. Time taken by train Q: 330/(x-5). (330/x) - (1/2) = 330/(x-5). (660 - x)(x - 5) = 330(2x) => x^2 - 5x + 3300 = 0 which has no real solution. On the other hand: (330/x) + (1/2) = 330/(x-5). (660 + x)(x - 5) = 330(2x) => x^2 - 5x - 3300 = 0 leads to (x - 60)(x + 55) = 0 which gives x = 60.

Time taken by train P = 330/60 = 5.5 h. Time taken by train Q = 330/55 = 6 h which is 30 min later.