ankur wants to travel from his home to his grandmom home by his car.the total distance between the two place is 600km.he covered the first 240 km at a speed of 40km/hr.what should his speed be for the remaining journey if he wants to cover the entire distance in 12 hours time
Answers
Answer:
Let the speed of the train be x km/h and speed of the bus be y km/h.
In case I:
If a man Travels 120 km by train, then
Distance covered by bus is (600-120)km = 480 km.
Time taken to cover 120 km by train = 120/x h.
Time taken to cover 480 km by bus = 480/y h.
[ Time = Distance/speed]
Total time of journey is 8 hours (GIVEN)
120/x + 480/y = 8
8(15/x +60/y) = 8
15/x +60/y = 1………..(1)
In case II:
If a man Travels 200 km by train, then
Distance covered by bus is (600-200)km = 400 km.
Time taken to cover 200 km by train = 200/x h.
Time taken to cover 400 km by bus = 400/y h.
[ Time = Distance/speed]
Total time of journey is 8 hours (GIVEN)
200/x + 400/y = 8 h 20 min
[ 8h 20 min = 8 (20/60) = 8 ⅓ h]
(200/x +400/y) = 25/3
25(8/x + 16/y) = 25/3
8/x + 16/y = ⅓
8(1/x +2/y) = ⅓
1/x +2/y = ⅓× ⅛
1/x +2/y = 1/24………..(2)
Putting 1/x = u and 1/y = v in eq i and ii,
15u + 60v = 1……… ….(3)
u + 2v =1/24…………..(4)
Multiply equation 4 by 15
15u + 30v = 15/24……….(6)
Subtract equation 6 from 3
15u + 60v = 1
15u + 30v = 15/24
(-) (-) (-)
------------------------
30v = -15/24 + 1
30v = (-15+24)/24
30v = 9/24
v = 9/(24× 30)
v = 3/(24×10)
v = 1/80
Putting v= 1/80 in equation 3
15u + 60v = 1
15 u + 60 (1/80)= 1
15u +3/4 = 1
15u = 1- 3/4
15 u = (4-3)/4
15 u = 1/4
u = 1 /(4×15)
u = 1/60
Now, u = 1/x = 1/60
x = 60
v = 1/y = 1/80
y = 80
Hence, a speed of train= 60km/h and speed of the bus= 80 km/h.
HOPE THIS WILL HELP YOU...
Step-by-step explanation:
Answer:
helloooo
Step-by-step explanation:
same as above mate