A Man walks certain distance at a certain speed. Had he walked 1/2 km/h faster, he would have taken one hour less. But, if he had gone 1km/h slower, he would have taken 3 hours longer, Find the distance

Solution : 

We know Formula :

 S(S+S1)/S1*T1=S(S+S2)/S2 *T2 when Dist is constant and thereis increase decrease in time & speed 

So putting value but before putting values cancel out S as a common element both side so,  we have 

S+1/2/1/2 * 1 = S-1/1 *3 

So,  S= 4 

Now puttinga again in base eq S =4 we have

D= 4*9/2 *2 =36 Ans