Question

Ritu is travelling by a car at a speed of

90 km/h and garima is travelling by a bus
at a speed of 60 km/h. if the total distance is
120 km. how much less time will ritu take
than garima?
is it 40min or 42 min
accurate ans pls with right explanation.

Answer 1

40 min is the answer

Explanation:

To solve this we need to convert all the units into SI units

for ritu,

speed= 90km/hr

= 90 × 1km/ 1hour

= 90×1000/3600 m/s

= 25m/s

distance = 120×1000m

time = distance/ speed

= 120000/25

= 4800sec

= 4800/60min

= 80 min

for garima,

distance =120×1000m

speed = 60km/hr

= 60×1000/3600 m/s

=100/6 m/

time = 120000/(100÷6)

= 7200sec

= 7200÷60 min

= 120 min

time difference is 120-80 = 40 min