A classroom table is 1 m wide and 1.75 m long. How many 39 cm wide chairs can fit around the table?

to do this, you get the perimeter of the table.

recall that the perimeter of a rectangle is given by,
P = 2*L + 2*W
where
L = length
W = width
substituting,
P = 2(1.75) + 2(1)
P = 3.5 + 2
P = 5.5 meters
then we convert this to centimeters. note that
1 meter = 100 centimeters
therefore 5.5 m = 550 cm
finally we divide 550 by 39 to get the number of chairs that could fit:
550/39 = 14.102
but since there is no 'decimal' chairs, we only take the whole number which is 14 chairs.

hope this helps~ :)