Question

7. One boat : Km. downstream and (x - 5) km. It takes a total of 285 minutes to travel upstream. If the difference between the downstream speed and the upstream speed of the boat is 3 km. / hour and the ratio of the speed of the boat in still water and the speed of the current is 9 : 1 respectively, then what is the value of x?​

Answer 1

Answer:

34.4

Let the speed of boat in still water = 9a km

speed of current = a km

According to question,

(9a + a) - (9a - a) = 3

10a - 8a = 3

2a = 3

a = 3

x9a+a + x−59a−a = 28560

x10a + x−58a = 28560

x10x32 + x−58x32 = 28560

x15 + x−512 = 28560

4x+5x−2560 = 28560

9x = 285 + 25

x = 3109

=> x = 34.4km