An order of award presentations has been devised for seven people: Jeff, Karen, Larry, Maria, Norm, Olivia, and Paul. Jeff, Larry, and Olivia are tall, and Karen, Maria, Norm, and Paul are short. In how many ways can the short people be presented first and then the tall people?

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.