Question

2.
A carpet of size 5 mx 2 m has 25 cm wide red border. The inner part of the carpet is
blue in colour (see fig.). Find the area of blue portion. What is the ratios of areas of red
portion to blue portion?
[NCERT Exemplar]
Red
Blue
3.
How much distance, in metres, a wheel of radius 21 cm will cover if it rotates 450 times?
[HOTS]
4.
A table cover of dimension 3 m 20 cm by 2 m 40 cm is spread on a table. If 20 cm of
the table cover is hanging all around the table. Find the area of the table cover which
is hanging outside the top of the table. Also, find the cost of polishing the table top
at * 20 per square metre.​

Answer 1

Answer:

In 1 rotation wheel will cover 2πr distance where r is the radius of wheel

For rotation of 450 times, it will cover 2πr×450

= 2×22×21×450/7

=59400cm =594 metres