Question

Hence, the length
EXERCISE 3.5
1. A person crosses a bridge 900 m long in 3 minutes. Find his speed in km/h and m/s.
2. Rishabh walks at 6 km/h and reaches his school in 1 hour 30 minutes. How far is his
school?
3. Archi rides at 20 km/h to her office, which is 15 km away. How long will she take to reach
the office?
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Answer 1

Step-by-step explanation:

1. distance = 900 m

time = 3 min or 180 s

speed (in m/s) = d/t = 900/180 = 5m/s

speed (in km/h) = 18 km/h

2. speed = 6 km/h

time = 1h 30 min or 1.5 h

distance = s×t = 6× 1.5 = 9 km

3. speed = 20 km/h

distance = 15 km

time = d/s = 15/20 = 3/4 h or 45 min