S O L U T I O N :
Section 3
12) a) Here, as we need that s or speed is the subject so speed should be in place of distance. So, we get
s = d/t
Here, s is speed, d is distance and t is the time
12) b) We know that :
Average Speed = Total Distance/Total Time
Here, total distance is given 748 km
total time 11.5 hrs
Avg. Speed = 748/11.5
Avg. Speed = 65.04 km/h
Hence, the answer is 65.04 km/h
13) a) We know that volume of a rabbit hutch is
Volume of rabbit hutch = ½ × b × h × l
Here,
b is the breadth, h is the height and l is the length
Volume= ½ × 50 cm × 50 cm × 2.5 m
Now, here Length is in metre so we need to convert to cm
1 m = 100 cm
2.5 m = 2.5 × 100 = 250 cm
So, now
Volume= ½ × 50 cm × 50 cm × 250 cm
Volume = 50 cm × 50 cm × 125 cm
Volume = 312,500 cm³
Hence, the volume of this hutch is 312,500 cm³
13) b) Let us assume that the orange be a sphere
So, volume of orange = 4/3πr³
Here, r is the radius and π is pi
radius is 4 cm
Volume = 4/3π(4)³
Volume = 4/3 × 64π
Volume = 85.33π cm³
Volume of the orange is 85.33π cm³