please read my doubt please explain me where i did wrong please explain me

Question

This is third time i asking same question none explain me and my doubt

 

A train running with 7/11 of its own speed reached a place in 22 hours how much time could be saved if the train would have run at its own speed

 

now let train speed be x
                     D       =       S         *          T
new speed 7x/11/22 = x*7/11        *         22
own speed 7x/11/22 =     x
 
now distance is same d= 7x/11/22

equation should be
7x/11/22=x*7/11*22
but answer get wrong

please explain me where i did wrong please explain me

Answer 1

Let R = full rate of speed.

 

D = (7/11)R(22) is distance traveled in 22 hrs, at 7/11 of full speed.

 

So D = 14R.

 

To go this same distance at full speed, D = Rt where t is unknown time.

Since D = 14R, we substitute & say  14R = Rt.  Dividing by R, we get t = 14 hours for the trip at full speed.