Mensuration – Class 6 Maths/Exercise 10.3/ NCERT Solutions.

Chapter 10 of CBSE/NCERT Class 6 Mathematics is about Mensuration. Here in this lesson you can find out text book solutions of Exercise 10.3

CBSE CLASS 6 MATHEMATICS
MENSURATION – Chapter 10 /Exercise 10.3

1. Find the areas of the rectangles whose sides are:
   a) 3 cm and 4 cm
   b) 12 m and 21 m
   c) 2 km and 3 km
   d) 2m and 70 cm
   Answer:
   a) Area of a rectangle = length X breadth
   Given length = 3 cm
   Breadth = 4 cm
   Area = 3 X 4 = 12 sq cm
   b) Area = length X breadth = 12 X 21 = 252 sq cm
   c ) Area = 2 X 3 = 6 sq km
   d) Area = length X breadth
   Length = 2m = 200 cm
   Breadth = 70 cm
   Area = 200 X 70 = 14000 cm = 1.40 sq m
2. Find the areas of the squares whose sides are:
   a) 10 cm
   b) 14 cm
   c) 5 m
   Answer:
   Area of a square = side X side
   a) Area = 10 X 10 = 100 sq cm
   b) Area = 14 X 14 = 196 sq cm
   c) Area = 5 X 5 = 25 sq m
3. The length and breadth of three rectangles are as given below:
   a) 9 m and 6 m
   b) 17 m and 3 m
   c) 4 m and 14 m
   Which one has the largest area and which one has the smallest?
   Answer:
   a) Area = length X breadth = 9 X 6 = 54 sq m
   b) Area = length X breadth = 17 X 3 = 51 sq m
   c) Area = length X breadth = 4 X 14 = 56 sq m
   It can be seen that (c) has the largest area and (b) has the smallest area.
4. The area of a rectangular garden 50 m long is 300 sq m. Find the width of the garden?
   Ans:
   Given Area = 300 sq m
   Length = 50 m
   Width = Area /length = 300 / 50 = 6m
5. What is the cost of tiling a rectangular plot of land 500 m long and 200 m wide at the rate of Rs 8 per hundred sq m?
   Answer:
   Here we want to find out the area of the given plot.
   Given length = 500 m
   Breadth = 200m
   Area = 500 X 200 = 100000 sq m
   Cost of tiling per hundred sq m = Rs 8
   Cost of tiling per 100000 sq m = 1000 X 8 = 8000 rupees
6. A table-top measures 2 m by 1m 50 cm. What is its area in square meters?
   Answer:
   Given length = 2m = 200 cm
   Breadth = 1m 50 cm = 150 cm
   Area = length X breadth = 200 X 150 = 30000 sq cm = 3 sq m
7. A room is 4 m long and 3 m 50 cm wide. How many square meters of carpet is needed to cover the floor of the room?
   Answer:
   Given length = 4 m = 400 cm
   Breadth = 3 m 50 cm = 350 cm
   Area = length X breadth = 400 X 350 = 140000 sq cm = 14 sq m
8. A floor is 5 m long and 4 m wide .A square carpet of sides 3 m is laid on the floor. Find the area of the floor that is not carpeted?
   Answer:
   First find the area of the floor.
   Given length = 5 m and breadth = 4 m
   Area = 5 X 4 = 20 sq m
   Then find the area of the carpet.
   Given side of the square carpet = 3 m
   Area of the carpet = 3 X 3 = 9 sq m
   Area of the floor that is not carpeted = 20 – 9 = 11 sq m
9. Five square flower beds each of sides 1 m are dug on a piece of land 5 m long and 4 m wide. What is the area of the remaining part of the land?
   Answer:
   Given length of the land = 5 m
   Breadth = 4 m
   Area of the land = 5 X 4 = 20 sq m
   Area of the flower bed of side 1m = 1 X 1 = 1 sq m
   Area of such 5 flower beds = 5 X1 = 5 sq m
   Area of the remaining part of the land = 20 – 5 = 15 sq m
10. By splitting the following figures into rectangles, find their areas (The measures are given in centimeters)
    a) Area of first rectangle = 4 X 2 = 8 sq cm
    Area of second rectangle = 6 X 1 = 6 sq cm
    Area of third rectangle = 3 X 2= 6 sq cm
    Area of fourth rectangle = 4 X 2 = 8 sq cm
    Total area of the figure = 8 + 6 + 6 + 8 = 28 sq cm
    b) Area of first rectangle = 3 X 1 = 3 sq cm
    Area of second rectangle = 3 X 1 = 3 sq cm
    Area of third rectangle = 3 X 1 = 3 sq cm
    Total area of the figure = 3 + 3+ 3 = 9 sq cm
11. Split the following shapes into rectangles and find their areas.
    (The measures are given in centimeters)
    a) Area of first rectangle = 12 X 2 = 24 sq cm
    Area of second rectangle = 8 X 2 =16 sq cm
    Total area of the figure = 24 + 16 = 40 sq cm
    b) The given figure can be split into 5 equal squares each of side 7 cm.
    Area of a square = side X side = 7 X 7 = 49 sq cm
    Therefore, the required area = 49 X 5 = 245 sq cm
    c) Area of the first rectangle = 5 X 1 = 5 sq cm
    Area of the second rectangle = 4 X 1 = 4 sq cm
    Total area of the figure = 5 + 4 = 9 sq cm
12. How many tiles whose length and breadth are 12 cm and 5 cm respectively will be needed to fit in a rectangular region whose length and breadth are respectively?
    a) 100 cm and 144 cm
    b) 70 cm and 36 cm.
    Answer:
    a) Total area of the rectangular region = 100 X 144 = 14400 sq cm
    Area of one tile = 12 X 5 = 60 sq cm
    Number of tiles required = 14400 /60 = 240 tiles
    b) Total area of the rectangular region = 70 X 36 = 2520 sq cm
    Area of one tile = 12 X 5=60 sq cm
    Number of tiles required = 2520 / 60 = 42 tiles
    =========================================