#### Answer

(a) 1Mm=1,000,000m
(b) 3,500,000m

#### Work Step by Step

Since the prefix M means one million, 1Mm is one million meters.
A unit fraction is a fraction with a value of 1. 1Mm=1,000,000m, so $\frac{1,000,000m}{1Mm}$=1. This fraction can be used to convert Mm to m.
$3.5Mm\times\frac{1,000,000m}{1Mm}= 3,500,000m$