time speed distance

Question

a car travels from p to q at a constant speed if its speed were increased by 10 kmhr it would have taken one hour lesser to cover the distance it would have taken further 45 lesser if the speed was further increased by 10 kmh what is the distance between the two cities

 

x=speed

y=time

D    =      S          *    T

             x+10      *    y-1  (why i put one because it is in hour) 

             x+20      *   (y-1)-45/60

 

now Distance is same

 

x+10(y-1)=x+20(y-1)-45/60 

 

is this equation is right if wrong where i did wrong please explain dont figure out different way i want to find out my mistake.

Answer 1

Did you mean 45 minutes in addition to 1 hour?  If so, then

D = (x+20)(y - 1 - 45/60) is correct, which is what you got.

 

Then set:

 

(x+10)(y-1) = (x+20)(y - 1 - 45/60)

 

I think your mistake was with the parenthesis in your very last equation.