Question

1) If a train A, 300m long crosses a bridge of length 200 m in 30 sec, then the speed of the train (in km/hr) is?

2) Speed of the boat in still water is 20 km/hr and the speed of the stream is 15km/hr. Find the total time taken to travel a distance of 30 km upstream and 50 km downstream??

3) If 243 is the third proportion
of a and b, where b:a = 9:1, then find the value of a and b.

I only need the answer..... Pls pls pls tell me faaaast...!!!....​​

Answer 1

Answer:

1) speed = distance/time

300m change in km= 300000

30sec change in hr = 30×60×60 = 108000

300000/108000 = 2.77km/hr

Answer 2

Answer:

2) Speed of the boat in still water is 20 km/hr and the speed of the stream is 15km/hr. Find the total time taken to travel a distance of 30 ...