Answer:

1. 125 miles

2. 4 hours

3. 6 km/sec

4. 1.5333333333 km/sec

5. 14

ANSWER AND SOLUTION

1. If a person drives his car in the speed 50 miles per hour, how far can he cover in 2.5 hours ?

FORMULA : d = s × t

Speed - 50 miles per hour

time - 2.5 hours

Distance : ?

• 50 × 2.5 = 125

2. Clark travels at a speed of 40 miles per hour. At the same rate, how long will he take to cover 160 miles distance ?

FORMULA :

t =

Distance - 160 miles

Speed - 40 miles per hour

time - ?

t =

• 160 ÷ 40 = 4

3. Frank covers 108 kms in 3 hours. What is his speed in meter per second ?

FORMULA:

s =

Distance - 180 kms

time - 3 hours

speed - ?

s =

• 108 ÷ 3 = 36 km/hr

1km/hr = 5/18 ms ( - negative 1 )

• at the height of ms is -1

36 × 5/18

• 36 × 5 = 180
• 180 ÷ 18 = 10

4. A a train covers 69 km in 45 minutes. Find the speed in km/hr.

Distance - 69 km

time - 45 minutes

speed - ?

69 ×

• 69 × 45 = 4,140

• 4. 140 ÷ 60 = 92km/hr

5. Kate travels a distance of 9 km from her house to the school by auto-rickshaw at 18 km/hr and returns on rickshaw at 15 km/hr. Find the average speed for the whole journey.

time taken ( school)

• 9/18hr = 1/2 hr

time taken (house to school)

• 9/15 = 3/5hr

total time

• 1/2 + 3/5 hr

Another total time of journey

=

=

Total distance

= 9 + 9km = 18 km

Average speed for the whole journey

×

=

• 18 × 10 = 180
• 1 × 11 = 11

• 180 ÷ 11 = 16.3 km/hr

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