#### Answer

(a) 220 reflectors are required.
(b) 221 reflectors are required.
It seems that it would be easier to perform calculations like this using the metric system, since the conversions between different units in the metric system are based on exponents of 10.

#### Work Step by Step

(a) We can find the number of reflectors that are required:
$\frac{(2.20~mi)(1760~yd/mi)}{17.6~yd} = 220$
220 reflectors are required.
(b) We can find the number of reflectors that are required:
$\frac{3540~m}{16.0~m} = 221$
221 reflectors are required.
It seems that it would be easier to perform calculations like this using the metric system, since the conversions between different units in the metric system are based on exponents of 10.