Q7. Simplify Factories:
16 9
+
26 = 52
Answers
Answer:
19) Case study: Surface area & Volume.
To develop critical and analysing skills amongst her children maths teacher showed her students a
video of 3D objects & asked the students to identify the 3D object. One such video was of PWD
workers constructing road using road roller. The cylindrical road roller made of iron was Im long. Its
inner diameter was 54 cm & thickness of the iron sheet rolled into the road roller is 9 cm
1) What is the outer radius of road roller?
a) 22 cm
36 cm
d) 11 cm
ii) What is the outer CSA of road roller?
a) 1548 cm
Tom?
b) 220 cm
c) 7200 cm
d) 440 cm
ii) If PWD workers constructed 1584 mo? road in one day, find the number of revolution that the road
roller made?
b) 1000
6100
iv) What will be the amount of iron used in road roller? (take = 3.14)
a) 178038 cm
b) 406944 cm c) 228906 cm d) 356076 cm
v) If 1 cc of iron weighs 10 gm, what will be the weight of road roller (in kg)?
a) 1780.38 kg
b) 4069.44 kg
d) 3560.76 kg
20) Case study: Statistics
a) 500
2289.06 kg