#### Answer

If this number is not divisible by 3, then it is not divisible
by 9.
If this number is divisible by 9, then it is divisible by 3.

#### Work Step by Step

r is a necessary condition for s means “if not r then not s.”

Published by
Cengage Learning

ISBN 10:
0-49539-132-8

ISBN 13:
978-0-49539-132-6

r is a necessary condition for s means “if not r then not s.”

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