Add my answer to Exercise 2.60.

Included are the following 2 files:

	Exercise_2.60.scm
	Test_for_Exercise_2.60.scm

Thank you!
							Lawrence R. Amlord
							   Jul 20th, 2013
							   Xi'an, China
Add my answer to Exercise 2.61.

Included are the following 2 files:

	Exercise_2.61.scm
	Test_for_Exercise_2.61.scm

Thank you!
							Lawrence R. Amlord
							   Jul 20th, 2013
							   Xi'an, China
Add my answer to Exercise 2.62.

Included are the following 2 files:

	Exercise_2.62.scm
	Test_for_Exercise_2.62.scm

Thank you!
							Lawrence R. Amlord
							   Jul 20th, 2013
							   Xi'an, China