Question

solution of this question quickly

Answer 1

hi friend,

the maximum time to reach school in time is 30minutes (9:30-10:00)=1/2hr

distance between them is 2km

let x be the time taken by him to travel 1km with a speed of 3kmph and y be the time taken by him to travel the remaining

then we know that

x+y should be equal to 1/2hr----(1)

given he travels 1km with a speed of 3kmph

so t =distance /speed

x=1/3hr

now.,by (1)

1/3+y=1/2

y=1/2-1/3

y=1/6 hr

now the speed he has to travel to be in time is distance /time

=1/1/6=6kmph

I hope this will help u :)

Answer 2

HI there !

Time to reach school = 10:00 - 9:30
                                  = 30 min  = 1/2 hr

distance between them is 2 km 

let x = time taken  to travel 1 km and
 speed = 3 km/hr
y =  time taken by him to travel the remaining distance
 
so ,

x + y =  1/2hr                               ===>(equation 1)

Speed = distance / time 

Time = distance / speed 

Distance = 1 km
Speed = 3 km/hr
Time = 1/3 hr

From equation (1) ,

1/3 + y =1/2

y = 1/2 - 1/3               [ lcm of 3 and 2 = 6 ]

y = 1/6 hr

Hence , time taken  to travel 1 km  = 1/3 hr
Time taken to travel the rest of the distance = 1/6 hr


Speed  to walk second km = distance / time

distance = 1 km
time = 1/6

speed = 1 / [1/6]
           = 6 km /hr