Interval between two flags = 50 m
Total number of flags needed
= 3000 + 50 = 60 flags
Since, flags are placed alternately, starting from red.
So, the flags will be placed as : red, blue, red, blue, …
Total number of flags = 60
Since, 60 is an even, they will be equally divided.
So, 30 red flags and 30 blue flags are needed.
NCERT Textbook Pages 60-61
Let Us Do
Longest Train Journey
The longest train journey in India is by The Vivek Express which runs from Dibrugarh in Assam to Kanniyakumari in Tamil Nadu. Look at the stations on the route shown in the table below and answer the questions.
1. The total length of the route from Dibrugarh to Kanniyakumari is _______________ km.
Solution:
4,187 km
2. The distance between Vijayawada and Jalpaiguri road is _______________.
Solution:
2,800 km – 983 km = 1817 km
3. Distance between Vijayawada and Visakhapatnam is _______________.
Solution:
2,800 km – 2,450 km = 350 km
4. Which two stations are farther apart—Guwahati and Dimapur or Bhubaneswar and Jalpaiguri Road?
Solution:
Distance between Guwahati and Dimapur = 556 km – 306 km – 250 km
Distance between Bhubaneswar and Jalpaiguri Road = 2007 km – 987 km = 1,020 km
∴ 1,020 > 250
So, Bhubaneswar and Jalpaiguri Road is farther apart the Guwahati and Dimapuri.
5. What is the distance between Guwahati and Coimbatore JN?
Solution:
3,675 km – 556 km = 3,119 km
NCERT Textbook Page 61
Let Us Measure
Measure the lines in the design and write their measurements in cm and mm.
Solution:
Do it yourself.
NCERT Textbook Page 62
Let Us Do
Soak some seeds of whole moong or black or white chana overnight. Next morning, take them out and wrap them in a moist cloth to sprout them. Over the next 4 days, take out one seed each day and measure the length of sprout. For ease of measurement, you can either place the seed on a paper and mark the length of the sprout, or use a thread to find its length.
Solution:
Do it yourself
Let Us Draw
Draw lines of the following lengths in your notebook using a scale.
1. 5 mm 5 mm
2. 3 cm 6 mm
3. 8 mm 3 mm
4. 36 mm
5. 67 mm
How did you draw lines of lengths 36 mm and 67 mm? Share your thoughts in class.
Solution:
Do it yourself
NCERT Textbook Pages 63-64
Let Us Do